WO2024051811A1 - 可回收聚合物气凝胶、蓄冷相变复合材料及制法和应用 - Google Patents

可回收聚合物气凝胶、蓄冷相变复合材料及制法和应用 Download PDF

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WO2024051811A1
WO2024051811A1 PCT/CN2023/117693 CN2023117693W WO2024051811A1 WO 2024051811 A1 WO2024051811 A1 WO 2024051811A1 CN 2023117693 W CN2023117693 W CN 2023117693W WO 2024051811 A1 WO2024051811 A1 WO 2024051811A1
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polymer
aerogel
phase change
recyclable
polymer aerogel
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PCT/CN2023/117693
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English (en)
French (fr)
Inventor
乔金樑
姚远
茹越
戚桂村
郭照琰
胡晨曦
高易
赖金梅
刘振杰
张晓红
宋志海
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中国石油化工股份有限公司
中石化(北京)化工研究院有限公司
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Priority claimed from CN202211100939.6A external-priority patent/CN117683175A/zh
Priority claimed from CN202211101085.3A external-priority patent/CN117720883A/zh
Application filed by 中国石油化工股份有限公司, 中石化(北京)化工研究院有限公司 filed Critical 中国石油化工股份有限公司
Publication of WO2024051811A1 publication Critical patent/WO2024051811A1/zh

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/10—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
    • C08J3/03—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media
    • C08J3/075—Macromolecular gels
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/28—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
    • C08L79/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
    • C08L79/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors

Definitions

  • the present invention relates to the field of porous materials, specifically to a recyclable polymer aerogel and its preparation method, recycling method and application; and a recyclable cold storage phase change composite material containing the recyclable polymer aerogel. , Recyclable cold storage phase change material with real-time temperature monitoring function and its preparation method and application.
  • Polymer aerogel refers to a new lightweight solid material composed of colloidal particles or polymer molecules clustered together, with a three-dimensional porous structure, and a gas dispersion medium filling the network pores. It has low density, It has the characteristics of high porosity and large specific surface area. They also have properties such as high temperature resistance, low thermal conductivity and low refractive index. It has been widely used in thermal and sound insulation materials, adsorption and separation, catalysis, energy storage and conversion, sound absorption and sound insulation, sensor platforms, antifouling and anti-adhesive materials, waterproof fabrics, proton exchange membranes, etc.
  • Polymer aerogels are usually prepared by sol-gel method and phase separation method.
  • the sol-gel method requires at least three processes: solution-sol conversion, sol-gel conversion, and gel-aerogel conversion. It requires up to 6-7 days of aging treatment, which is extremely time-consuming.
  • the phase separation method can first use an organic solvent to make a polymer solution. After gelation, the organic solvent is replaced with water to make a hydrogel, and then an aerogel is made. The disadvantage of this method is that a large amount of organic solvent must be processed.
  • Polymer aerogels can also be directly prepared using aqueous solutions, but the aerogel products must be cross-linked and hydrophobically post-treated, which is a complicated process.
  • polymer aerogels especially cross-linked low-density polymer aerogels, not only cause environmental pollution during the preparation process, but the products are also difficult to recycle. Therefore, as consumption increases, polymer aerogels will produce more serious "white pollution” problems than ordinary plastic products, which restricts the industrial application of polymer aerogels. Obviously, the development of low-pollution recyclable polymer aerogels is an urgent technical problem to be solved in aerogel technology.
  • Phase change materials have high energy storage densities, providing a compact and feasible solution to the supply-demand imbalance.
  • Phase change materials are mainly divided into organic and inorganic phase change materials. Compared with inorganic phase change materials, organic phase change materials have received more attention in practical applications due to their advantages such as non-toxicity, slight supercooling and good cycle stability.
  • organic phase change materials will encounter the risk of leakage when directly used as energy storage materials, and it is very necessary to encapsulate phase change materials to prevent leakage problems.
  • organic phase change materials also need to consider reprocessability and recyclability to avoid environmental pollution and resource waste.
  • the present invention provides a recyclable polymer aerogel and its preparation method, recycling method and application.
  • a polymer containing a maleimide group-containing structural unit is prepared. into an aerogel, which broadens the application range of copolymers containing structural units containing maleic anhydride groups and maleimide groups; more importantly, the aerogels prepared in the present invention have extremely high recovery efficiency , after using ammonia water to dissolve and recover, the recovery efficiency can be higher than 99%, and the airgel preparation and recovery process does not require Using any organic solvent, it has the characteristics of low energy, high efficiency, green and environmental protection.
  • the polymer aerogel of the present invention has good hydrophobic and water-resistant properties. At the same time, it has low thermal conductivity, low density, and good heat resistance. It can be used in a variety of fields and has extremely high application value.
  • the inventor of the present invention found in the research that when a copolymer containing maleic anhydride and its derivative groups such as maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt is One or several polymer raw materials in the structural units of the group are dissolved in ammonia water to obtain a polymer aqueous solution. After freeze-drying, a copolymer aerogel containing maleic anhydride groups and maleimide groups with hydrophobic and water-resistant properties was prepared by heat treatment.
  • the three-dimensional pore structure of the airgel during heat treatment It can remain stable and obtain a hydrophobic and water-resistant polymer aerogel without the need for cross-linking and hydrophobization treatments, which is green and environmentally friendly and reduces preparation time and material costs.
  • the polymer aerogel prepared by the method of the present invention can be recycled under the action of ammonia water.
  • the special properties of this type of polymer can be used to achieve repeated conversion of water-soluble polymers and water-resistant hydrophobic aerogels. The above process does not require Using organic solvents is more environmentally friendly.
  • the present invention also provides a recyclable cold storage phase change composite material and its preparation method and application.
  • the recyclable cold storage phase change composite material not only has cold storage capacity, but also can be recycled It is recycled and at the same time has the characteristics of low leakage.
  • the present invention also provides a recyclable cold storage phase change composite material with a real-time temperature monitoring function, which not only has cold storage capacity, is recyclable, and has low leakage, but also has a real-time temperature monitoring function.
  • a first aspect of the present invention is to provide a polymer aerogel, the polymer containing a structural unit containing a maleic anhydride group and a structural unit containing a maleimide group.
  • the maleic anhydride group refers to Maleimide group Refers to Maleimide group
  • the polymer is a carbon chain polymer in which heteroatoms O and N are present in the pendant groups.
  • the polymer contains male
  • the molar proportion of the structural units of the imide group is 5%-70%, preferably 10%-60%; more preferably 20%-50%, such as 20%, 25%, 30%, 35%, 40% , 45%, 50%, and any two values or any interval between any two values.
  • the polymer can be selected within a wide range.
  • the polymer is derived from a polymer containing maleic anhydride, maleimide, maleic acid and One or more polymer raw materials of the structural units of ammonium salt, maleamic acid and ammonium salt group.
  • the maleic anhydride group refers to The maleimide group refers to Maleic acid and ammonium salt groups, maleamic acid and ammonium salt groups refer to In the formula, M is the same or different, and each is hydroxyl, amino or ammonium (-ONH 4 ).
  • the polymer is a carbon chain polymer in which heteroatoms O and N are present in the pendant groups.
  • the polymer raw materials include but are not limited to one or more polymerized monomers selected from the group consisting of maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt, and of olefin monomers Polymer; for example, the present invention can also be realized when the polymer raw material is such as styrene maleic anhydride vinyl silicone oil copolymer.
  • the copolymers of the above polymerized monomers and olefin monomers including one or more of maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt have lower raw material costs. .
  • the polymer raw material is a polymerized monomer including one or more of maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt, and olefin monomer.
  • the olefin monomer is at least one of ⁇ -methylstyrene, styrene, isobutylene, and vinyl acetate.
  • the polymer raw material is a polymerized monomer including one or more of maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt, and ⁇ -methane. Alternating copolymer of one of styrene, styrene and isobutylene.
  • the polymer raw materials in the present invention include but are not limited to at least one of styrene maleic anhydride copolymer, styrene maleic anhydride vinyl silicone oil copolymer, and maleic anhydride isobutylene copolymer.
  • the polymer raw material in the present invention includes at least one of styrene maleic anhydride copolymer and maleic anhydride isobutylene copolymer.
  • the polymer aerogel can be dissolved in ammonia water at 0-150°C to form a polymer aqueous solution; preferably, the polymer aqueous solution has been pre-frozen, freeze-dried, and heat treated , polymer aerogel can be recovered. Based on this, the polymer aerogel of the present invention can be recycled conveniently and environmentally friendly.
  • the thermal conductivity of the polymer aerogel is 0.025-0.05W/(m ⁇ k), preferably 0.027-0.04W/(m ⁇ k).
  • the polymer aerogel of the present invention has the characteristics of low thermal conductivity, does not require any treatment, and can be directly used as a thermal insulation material.
  • the density of the polymer aerogel is 10-100kg/m 3 , preferably 15-75kg/m 3 , specifically, for example, 15kg/m 3 , 35kg/m 3 , 45kg/m 3 , 55kg/m 3 , 65kg/m 3 , 75kg/m 3 , and any two values or any interval between any two values; and/or the polymer aerogel is a porous material.
  • the polymer airgel of the present invention has high porosity and is a three-dimensional porous material that can be used as a carrier. For example, as a framework-loaded organic phase change material, To avoid leakage of phase change materials, the prepared phase change composite materials can also be recycled through ammonia water.
  • the inventor of the present invention has discovered through research that when the polymer aerogel is a styrene maleic anhydride maleimide copolymer aerogel, it also has photoluminescence properties and can generate light signals as the temperature changes. Variety.
  • the photoluminescence properties of the polymerized aerogel in the present invention can also be used as an indicator material showing temperature changes.
  • the static water contact angle of the polymer aerogel is above 100°, preferably above 110°, and more preferably above 135°.
  • the polymer aerogel is insoluble in water. It is preferable to soak the polymer aerogel in water at 20-40°C for 24 hours, preferably for 72 hours, and more preferably for 168 hours. , will not dissolve in aqueous solutions forming polymers.
  • the polymer aerogel of the present invention has the characteristics of super lipophilicity and hydrophobicity, and can be directly used as an oil-water separation material without any treatment.
  • the polymer aerogel is formed by converting the polymer aerogel containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt groups into It is prepared by reacting one or several polymer raw materials in the structural unit with ammonia water in a closed condition, and then pre-freezing, freeze-drying, and heat treatment, dehydration and deamination.
  • the polymer aerogel in the present invention can be an anisotropic aerogel or an isotropic aerogel.
  • anisotropic aerogel The difference between anisotropic aerogel and isotropic aerogel is that the pore structure is different.
  • the aerogel pore structure of anisotropic aerogel shows long-range order, mainly due to the directional growth of ice crystals in the pre-freezing stage of the aerogel.
  • impurities polymers in the present invention
  • the impurities aggregate to form pore walls; the subsequent freeze-drying removes ice to obtain a porous aerogel. Therefore, anisotropic aerogels can be obtained by varying the temperature of the unidirectional cold source during pre-freezing.
  • the one-way cold source temperature includes pre-freezing, using liquid nitrogen as the low-temperature cold source, placing the mold on a copper pillar immersed in liquid nitrogen, and the ice crystals grow upward from the bottom of the mold, and finally Aerogels that form anisotropic pore structures.
  • Anisotropic aerogels have different airgel pore structures, different axial and radial thermal conductivity coefficients, and different material and sound transmission rates. Anisotropic aerogels/isotropic airgels can be selected according to different application situations. Sexual aerogels. For example, when the phase change material is packaged in the present invention, the inventor of the present invention found that the leakage amount can be significantly reduced by using the preferred anisotropic aerogel, and there is no requirement for the direction of the anisotropic aerogel.
  • the second aspect of the present invention provides a method for preparing a polymer aerogel, which includes adding groups containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt.
  • One or several polymer raw materials in the structural units react with ammonia water under closed conditions, and then undergo pre-freezing, freeze-drying, heat treatment, dehydration and deamination to obtain the polymer aerogel.
  • the aerogel preparation method of the present invention only requires heat treatment of water-soluble aerogels, avoiding the introduction of cross-linking agents or hydrophobic treatment to prepare hydrophobic and water-resistant aerogels.
  • the preparation method is simple, easy, green and environmentally friendly, and is suitable for various types of applications. Preparation of maleimide copolymer aerogels. No cross-linking agent is added to the airgel preparation method of the present invention.
  • the preparation method includes the following specific steps:
  • step (2) Pre-freeze the polymer aqueous solution obtained in step (1) and then freeze-dry it to obtain a water-soluble polymer (i.e., polymer aerogel precursor);
  • step (3) Heat-treat the water-soluble polymer obtained in step (2) to obtain the polymer aerogel.
  • the amount of polymer raw materials, ammonia water, etc. in step (1) can be selected within a wide range.
  • the mass fraction of the polymer raw material dosage is 0.1%-30%, preferably 0.5%-10%, more preferably 1%-5%, based on the mass of ammonia in ammonia water,
  • the mass fraction of ammonia usage is 0%-30%, preferably 0.01%-10%, more preferably 0.1%-1%, and the remaining component is water.
  • the reaction conditions in step (1) can be selected within a wide range.
  • the reaction conditions include: the reaction temperature is 0-200°C, preferably 50°C. -150°C, more preferably 80-100°C, and/or the reaction time is 0.01-100h, preferably 0.5- 10h, more preferably 1-5h.
  • the reaction pressure is not particularly limited, but it is preferably carried out under normal pressure.
  • step (2) includes pre-freezing the aqueous polymer solution obtained in step (1) in a mold to obtain ice cubes.
  • the mold can be of any shape and size and can be customized according to the desired aerogel. Freezing can use cold sources such as refrigerators, or liquid nitrogen can be used for freezing.
  • the temperatures of the cold sources in all directions of the aqueous solution are the same or different; in this step, if the temperatures of the cold sources in all directions of the corresponding mixed liquid during pre-freezing are the same, then the prepared aerogel is isotropic; Anisotropic aerogels can be prepared with different directional cold source temperatures.
  • the temperature of the unidirectional cold source is different during pre-freezing to obtain anisotropic aerogel.
  • the one-way cold source temperature including but not limited to when pre-freezing, using liquid nitrogen as the low-temperature cold source, placing the mold on a copper pillar immersed in liquid nitrogen, and ice crystals grow upward from the bottom of the mold. implementation.
  • the pre-freezing conditions can be conventional temperature conditions in the art, and the present invention has no particular limitations.
  • the freeze-drying conditions can be selected within a wide range, and the present invention is not particularly limited.
  • the freeze-drying conditions include: the temperature is below -10°C, for example It can be -20°C or lower, or it can be -30°C or lower.
  • the vacuum degree of freeze-drying can be selected in a wide range. In a preferred embodiment of the invention, the vacuum degree is 1000Pa or lower, for example It may be 100Pa or less or 10Pa or less.
  • the above freeze-drying conditions can be flexibly selected based on cost, efficiency and the conventional operating methods of the equipment.
  • the freeze-drying process can use various freeze-drying equipment in the existing technology, such as freeze dryers, freeze spray dryers, industrial freeze dryers, etc.
  • the conditions of heat treatment in step (3) can be selected within a wide range.
  • the conditions of heat treatment in step (3) include: the temperature is 100-300°C, preferably The temperature is 130-200°C, more preferably 150-190°C, and/or the time is 0.1-10h, preferably 0.5-3h, more preferably 1-2h.
  • the polymer raw material can react with ammonia water to obtain a water-soluble polymer.
  • the polymer raw material can be selected within a wide range.
  • the polymer raw material contains maleic anhydride, maleimide, maleic acid. and a polymer of one or more of the structural units of ammonium salt, maleamic acid and ammonium salt group; preferably, the polymer raw material includes maleic anhydride, maleimide, maleic acid and a copolymer of one or more polymerized monomers and olefin monomers selected from ammonium salt, maleamic acid and ammonium salt; more preferably, the olefin monomer includes ⁇ -methylstyrene, styrene, At least one kind of isobutylene.
  • the polymer raw material includes but is not limited to at least one of styrene maleic anhydride copolymer, styrene maleic anhydride vinyl silicone oil copolymer, and maleic anhydride isobutylene copolymer.
  • the polymer raw material includes at least one of styrene maleic anhydride copolymer and maleic anhydride isobutylene copolymer.
  • the preparation process of the polymer aerogel of the present invention includes the following steps: a. Containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt base One or several polymer raw materials in the group's structural units react with ammonia in a closed container and heat to prepare a polymer aqueous solution; b. Pour the polymer aqueous solution into the mold, and then pre-freeze it to completely After freezing into ice cubes, freeze-dry in a freeze dryer for a certain period of time to obtain a water-soluble polymer; c. Heat-treat the water-soluble polymer under constant temperature conditions to obtain water-resistant maleimide through dehydration and deamination. base aerogel.
  • the above-mentioned polymer raw materials are polymers that have been disclosed in the prior art, and can be commercially available from the prior art, or prepared according to methods disclosed in the prior art.
  • the material of the sealed container is not particularly limited, and it can be a metal, non-metal, polymer or other material container.
  • the "and/or" involved in the present invention means that one of the two conditions before and after "and/or" can be selected, or the two conditions can coexist.
  • a third aspect of the present invention is to provide a method for recycling polymer aerogel, which is the polymer aerogel described in the first aspect or the preparation method described in the second aspect.
  • the prepared polymer aerogel is recycled by recycling the polymer aerogel and/or containing the polymer aerogel.
  • the material of the compound aerogel and ammonia are mixed and reacted under closed conditions until an aqueous solution containing the recycled polymer is obtained, and insoluble matter is optionally removed to obtain an aqueous solution of the recycled polymer.
  • This airgel recycling method does not require the introduction of organic solvents, and does not require high-temperature and high-pressure stirring. It only requires a certain concentration of ammonia water, preferably kept below 100 degrees Celsius, and can achieve rapid and efficient recycling. This method has low energy consumption, little pollution, high efficiency, and the recovered The polymer solution can again be used in the preparation of polymer aerogels.
  • the recycling method of the polymer aerogel of the present invention is as follows: placing the polymer aerogel in a certain concentration of ammonia water, placing it in a closed container, heating it at a certain temperature, and waiting until it is completely dissolved to obtain an aqueous solution of the copolymer. .
  • the conditions of the mixing reaction in the recovery method can be selected within a wide range.
  • the temperature of the mixing reaction is 0-200°C, preferably 50-150°C, and more preferably The temperature is 80-100°C, and/or the mixing reaction time is 0.01-100h, preferably 0.5-10h, more preferably 1-5h.
  • the reaction pressure is not particularly limited, but it is preferably carried out under normal pressure.
  • the recovery method further includes pre-freezing, freeze-drying, and heat treating the aqueous solution of the recovered polymer to recover the polymer aerogel.
  • the temperatures of the cold sources in all directions of the aqueous solution during pre-freezing are the same or different. If the temperature of the cold source in all directions of the aqueous solution is the same during pre-freezing, the aerogel prepared is isotropic; if the temperature of the cold source in all directions of the aqueous solution is different during pre-freezing, anisotropic aerogels can be prepared. Preferably, the temperature of the unidirectional cold source is different during pre-freezing to obtain anisotropic aerogel.
  • the one-way cold source temperature includes but not limited to when pre-freezing, using liquid nitrogen as the low-temperature cold source, placing the mold on a copper pillar immersed in liquid nitrogen, and ice crystals grow upward from the bottom of the mold. implementation.
  • the freeze-drying conditions can be selected within a wide range, and the present invention is not particularly limited.
  • the freeze-drying conditions include: the temperature is below -10°C, for example It may be -20°C or lower, or it may be -30°C or lower, and/or the vacuum degree may be 1000Pa or lower, for example, it may be 100Pa or lower, or it may be 10Pa or lower.
  • the conditions of heat treatment can be selected within a wide range.
  • the conditions of heat treatment include:
  • the temperature is 100-300°C, preferably 130-200°C, more preferably 150-190°C and/or, and the time is 0.1-10h, preferably 0.5-3h, more preferably 1-2h.
  • a fourth aspect of the present invention provides a recycled polymer aerogel obtained according to the recycling method described in the third aspect.
  • the performance of the polymer aerogel obtained by the above method is equivalent to that of the polymer aerogel prepared for the first time and can be recycled again.
  • the fifth aspect of the present invention is to provide a polymer aerogel as described in the first aspect, a polymer aerogel prepared by the preparation method as described in the second aspect, or a recycled material as described in the fourth aspect.
  • Polymer aerogels are used as porous materials, preferably as carriers, filter materials and adsorbed organic phase change materials, or as oil-water separation materials and thermal insulation materials.
  • the polymer aerogel can be used as a load material, such as a load phase change material to avoid leakage.
  • the hydrophobic polymer aerogel of the present invention can be used for oil-water separation without surface treatment. It can be used as a thermal insulation aerogel. It can also be blended with other components to prepare multi-component aerogels. When it is not dissolved in ammonia water, multi-component aerogels can also be recovered through ammonia water.
  • the sixth aspect of the present invention is to provide a recyclable cold storage phase change composite material, including a polymer aerogel and a phase change material loaded in the polymer aerogel; wherein, the polymer aerogel It is the polymer aerogel described in the first aspect, the polymer aerogel prepared by the preparation method described in the second aspect, or the recycled polymer aerogel described in the fourth aspect.
  • the content of the phase change material and polymer aerogel in the recyclable cold storage phase change composite material can be selected within a wide range.
  • the recyclable cold storage phase When the total mass of the composite material is 100%, the content of the polymer aerogel is 2%-20%, preferably 4%-10%, for example, it can be 4%, 5%, 6%, 7%, 8% %, 9%, 10%, and any two values or any interval between any two values; the content of the phase change material is 80%-98%, preferably 90%-96%.
  • the sum of the total mass of the polymer aerogel and the phase change material is 100%.
  • the phase change material can be selected in a wide range, as long as it has cold storage properties.
  • the phase change material includes but is not limited to an organic phase change material.
  • the phase change of the organic phase change material is The temperature is (-10)-30°C, and/or the latent heat of phase change is 55-280J/g; more preferably, it is an alkane organic phase change material, and even more preferably it is decane, dodecane, or tetradecane. At least one.
  • the leakage amount of the phase change material in the recyclable cold storage phase change composite material is less than 10wt%, preferably less than 5wt%, and more preferably Less than 2wt%.
  • the polymer aerogel in the cold storage phase change composite material can be anisotropic aerogel or isotropic aerogel.
  • anisotropic aerogel The difference between anisotropic aerogel and isotropic aerogel is that the pore structure is different.
  • the aerogel pore structure of anisotropic aerogel shows long-range order, mainly due to the directional growth of ice crystals in the pre-freezing stage of the aerogel.
  • impurities polymers in the present invention
  • the impurities aggregate to form pore walls; the subsequent freeze-drying removes ice to obtain a porous aerogel. Therefore, anisotropic aerogels can be obtained by varying the temperature of the unidirectional cold source during pre-freezing.
  • the one-way cold source temperature includes but not limited to when pre-freezing, using liquid nitrogen as the low-temperature cold source, placing the pre-freezing container on a copper column immersed in liquid nitrogen, and the ice crystals rise from the bottom of the pre-freezing container. Grows upward, eventually forming an aerogel with anisotropic pore structure.
  • Anisotropic aerogels have different airgel pore structures, different axial and radial thermal conductivity coefficients, and different material and sound transmission rates.
  • Anisotropic aerogels/isotropic aerogels can be selected according to different application situations. glue. For example, when the phase change material is packaged in the present invention, the inventor of the present invention found that the leakage amount can be significantly reduced by using the preferred anisotropic aerogel, and there is no requirement for the direction of the anisotropic aerogel.
  • the polymer aerogel in the cold storage phase change composite material is an anisotropic aerogel, preferably an anisotropic aerogel obtained by different temperatures of the one-way cold source during pre-freezing. gel.
  • the leakage amount of the phase change material in the recyclable cold storage phase change composite material is lower.
  • the polymer aerogel is soluble in 0-150°C In ammonia water, a polymer-containing solution is formed.
  • the polymer-containing solution is pre-frozen, freeze-dried, and heat-treated to recover the polymer aerogel.
  • the thermal conductivity of the polymer aerogel is 0.05W/(m ⁇ k) or less, preferably 0.04W/(m ⁇ k) or less.
  • the polymer aerogel of the present invention has the characteristics of low thermal conductivity, does not require any treatment, and can be directly used as a thermal insulation material.
  • the density of the polymer aerogel is 100kg/m 3 or less, preferably 10-100kg/m 3 , preferably 15-80kg/m 3 specifically, for example, 15kg /m 3 , 35kg/m 3 , 45kg/m 3 , 55kg/m 3 , 65kg/m 3 , 75kg/m 3 , 80kg/m 3 , and any two values or any interval between any two values; and/or,
  • the polymer aerogel is a porous material.
  • the polymer aerogel of the present invention has high porosity and is a porous material that can be used as a carrier. For example, it can be used as a framework to load organic phase change materials to avoid leakage of phase change materials.
  • the prepared phase change composite materials can also be recycled through ammonia water.
  • the polymer contains male
  • the molar proportion of the structural units of the imide group is 5%-70%, preferably 10%-60%; more preferably 20%-50%, such as 20%, 25%, 30%, 35%, 40% , 45%, 50%, and any two values or any interval between any two values.
  • the polymer can be selected within a wide range.
  • the polymer is derived from a polymer containing maleic anhydride, maleimide, maleic acid and One or more polymer raw materials of the structural units of ammonium salt, maleamic acid and ammonium salt group.
  • the maleic anhydride group refers to The maleimide group refers to Maleic acid and ammonium salt groups, maleamic acid and ammonium salt groups refer to In the formula, M is the same or different, and each is hydroxyl, amino or ammonium (-ONH 4 ).
  • the polymer is a carbon chain polymer in which heteroatoms O and N are present in the pendant groups.
  • the polymer raw material is a polymerized monomer including one or more of maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt, and olefin monomer.
  • Copolymer more preferably, the olefin monomer is at least one of ⁇ -methylstyrene, styrene, and isobutylene.
  • the polymer aerogel can be dissolved in ammonia water at 0-150°C to form a polymer-containing solution; preferably, the polymer-containing solution is prefrozen and freeze-dried. , heat treatment, the polymer aerogel can be recovered. Based on this, the polymer aerogel of the present invention can be recycled conveniently and environmentally friendly.
  • the polymer aerogel has photoluminescence properties and can change the light signal as the temperature changes.
  • the photoluminescence properties of the polymer aerogel in the present invention can also be used as an indicator material showing temperature changes.
  • the static water contact angle of the polymer aerogel is above 100°, preferably above 110°, and more preferably above 135°.
  • the polymer aerogel is insoluble in water. It is preferable to soak the polymer aerogel in water at 20-40°C for 24 hours, preferably for 72 hours, and more preferably for 168 hours. , will not dissolve in aqueous solutions forming polymers.
  • the polymer aerogel of the present invention has the characteristics of super lipophilicity and hydrophobicity, and can be directly used as an oil-water separation material without any treatment.
  • the preparation method of the polymer aerogel includes adding a compound containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt.
  • a compound containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt One or several polymer raw materials in the structural units of the group react with ammonia water under closed conditions, and then undergo pre-freezing, freeze-drying, and heat treatment for dehydration and deamination to obtain the polymer aerogel.
  • the aerogel preparation method of the present invention only requires heat treatment of water-soluble aerogel, avoiding the introduction of The cross-linking agent or hydrophobic treatment is used to prepare hydrophobic and water-resistant aerogels.
  • the preparation method is simple, easy, green and environmentally friendly, and is suitable for the preparation of various types of maleimide copolymer aerogels. No cross-linking agent is added to the airgel preparation method of the present invention.
  • the seventh aspect of the present invention is to provide a method for preparing the recyclable cold storage phase change composite material described in the sixth aspect, including loading the phase change material in the polymer aerogel; preferably, A polymer aerogel is first prepared, and then the phase change material is loaded in the polymer aerogel.
  • the method of loading the phase change material in the polymer aerogel can be any of the various loading methods available in the prior art. Specifically, the loading of the phase change material can be achieved by filling and injecting the phase change material in a liquid state so that the phase change material is adsorbed and/or penetrated into the composite aerogel.
  • the preparation method of the polymer aerogel includes one or more structural units containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt groups.
  • the polymer raw materials react with ammonia water under closed conditions, and then undergo pre-freezing, freeze-drying, and heat treatment for dehydration and deamination to obtain the polymer aerogel.
  • the aerogel preparation method of the present invention only requires heat treatment of water-soluble aerogels, avoiding the introduction of cross-linking agents or hydrophobic treatment to prepare hydrophobic and water-resistant aerogels.
  • the preparation method is simple, easy, green and environmentally friendly, and is suitable for various types of applications. Preparation of maleimide copolymer aerogels.
  • the preparation method includes the following steps: (1) adding a base containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt One or several polymer raw materials in the structural units of the group react with ammonia water under closed conditions to obtain a polymer aqueous solution; (2) The polymer aqueous solution obtained in step (1) is first pre-frozen, and then frozen Dry to obtain a water-soluble polymer (i.e., polymer aerogel precursor); (3) Heat-treat the water-soluble polymer obtained in step (2) to obtain the polymer aerogel; (4) Apply the Phase change materials are loaded in the polymer aerogel.
  • a base containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt One or several polymer raw materials in the structural units of the group react with ammonia water under closed conditions to obtain a polymer aqueous solution.
  • the polymer aqueous solution obtained in step (1) is first pre-frozen, and
  • the amount of polymer raw materials, ammonia water, etc. in step (1) can be selected within a wide range.
  • the mass fraction of the polymer raw material dosage is 0.1%-30%, preferably 1%-10%, more preferably 2%-5%, based on the mass of ammonia in ammonia water,
  • the mass fraction of ammonia in the raw material is 0.001%-30%, preferably 0.01%-10%, more preferably 0.1%-1%, and the remaining component is water.
  • the reaction conditions in step (1) can be selected within a wide range.
  • the reaction conditions include: the reaction temperature is 0-200°C, preferably 50°C. -150°C, more preferably 80-100°C, and/or the reaction time is 0.01-100h, preferably 0.5-10h, more preferably 1-5h.
  • step (2) includes pre-freezing the polymer aqueous solution obtained in step (1) in a pre-freezing container to obtain ice cubes.
  • Pre-frozen containers can be of any shape and size and can be customized to the desired aerogel. Freezing can use cold sources such as refrigerators, or liquid nitrogen can be used for freezing.
  • the aerogel prepared is isotropic; if the cold source temperature in all directions of the pre-freezing container is different, anisotropic aerogel can be prepared.
  • anisotropic aerogels can be obtained by using different temperatures of the unidirectional cold source during pre-freezing.
  • the one-way cold source temperature including but not limited to pre-freezing, using liquid nitrogen as the low-temperature cold source, placing the pre-freezing container on a copper column immersed in liquid nitrogen, and ice crystals growing upward from the bottom of the container , such an implementation.
  • the pre-freezing conditions can be conventional temperature conditions in the field.
  • the present invention is not particularly limited, as long as the polymer aqueous solution is frozen into ice.
  • the freeze-drying conditions can be selected within a wide range, and the present invention is not particularly limited.
  • the freeze-drying conditions include: the temperature is below -10°C, for example It can be -20°C or lower, or it can be -30°C or lower.
  • the vacuum degree of freeze-drying can be selected in a wide range. In a preferred embodiment of the invention, the vacuum degree is 1000Pa or lower, for example It may be 100Pa or less or 10Pa or less.
  • the above freeze-drying conditions can be flexibly selected based on cost, efficiency and the conventional operating methods of the equipment.
  • the freeze-drying process can use various freeze-drying equipment in the existing technology, such as freeze-drying Machine, freeze spray dryer, industrial freeze dryer, etc.
  • the conditions for heat treatment in step (3) can be selected within a wide range.
  • the conditions for heat treatment in step (3) include:
  • the temperature is 100-300°C, preferably 130-200°C, more preferably 150-190°C, and/or the time is 0.1-10h, preferably 0.5-3h, more preferably 1-2h.
  • the reaction pressure is not particularly limited, but it is preferably carried out under normal pressure.
  • the polymer raw material can be selected within a wide range.
  • the polymer raw material contains maleic anhydride, maleimide, maleic acid. and a polymer of one or more of the structural units of ammonium salt, maleamic acid and ammonium salt group; preferably, the polymer raw material includes maleic anhydride, maleimide, maleic acid and a copolymer of one or more polymerized monomers and olefin monomers selected from ammonium salt, maleamic acid and ammonium salt; more preferably, the olefin monomer includes ⁇ -methylstyrene, styrene, At least one of isobutylene and vinyl acetate.
  • the polymer raw materials include but are not limited to at least one of styrene maleic anhydride copolymer, methylstyrene maleic anhydride copolymer, and maleic anhydride isobutylene copolymer.
  • the above-mentioned polymer raw materials are polymers that have been disclosed in the prior art, and can be commercially available from the prior art, or prepared according to methods disclosed in the prior art.
  • the material of the sealed container is not particularly limited, and it can be a metal, non-metal, polymer or other material container.
  • the preparation process of the polymer aerogel of the present invention includes the following steps: a. Containing maleic anhydride, maleimide, maleic acid and ammonium salt, maleamic acid and ammonium salt base One or several polymer raw materials in the structural units of the group react with ammonia in a closed container and heat to prepare a polymer aqueous solution; b. Pour the polymer aqueous solution into a pre-freezing container, and then pre-freeze , after being completely frozen into ice cubes, put it into a freeze dryer and freeze-dry for a certain period of time to obtain a water-soluble polymer; c. Heat-treat the water-soluble polymer under constant temperature conditions to obtain water-resistant maleic acid through dehydration and deamination. Imine-based aerogels.
  • the cold source temperatures in all directions of the solution are the same or different. More preferably, when pre-freezing, the solution The cold source temperature in each direction of the pre-frozen solution is different, and anisotropic aerogel is obtained; most preferably, the cold source temperature of the pre-frozen solution is different in one direction, and anisotropic aerogel is obtained.
  • the cold source temperatures in all directions of the polymer aqueous solution obtained in step (1) are different, preferably the cold source temperatures in one direction are different.
  • the mold before pre-freezing in step (2), the mold is inserted into the aqueous polymer solution obtained in step (1), and the mold can be inserted into the bottom to contact the bottom of the pre-freezing container. , can also leave a distance from the bottom of the pre-freezing container, preferably the latter; and after the heat treatment in step (3), optionally take out the mold to obtain a polymer aerogel with a cavity, and add the phase in step (4) Variable materials are filled into the polymer aerogel. In this way, the pre-stored product can be placed in the cavity left after taking out the mold to facilitate storage.
  • the mold in the present invention When the mold in the present invention has a cavity structure, it does not need to be taken out, and the pre-stored material can be placed in the cavity of the mold during use. At the same time, refrigerated items (such as vaccines, medicines, etc.) are placed in the cavity, making the cold storage environment in which the refrigerated items are located more uniform and the preservation effect better.
  • refrigerated items such as vaccines, medicines, etc.
  • the present invention has no special restrictions on the selection of the mold.
  • the material can be glass, plastic, metal, etc.; the mold can be solid or with a cavity structure, and its shape is not limited. , preferably cylindrical, columnar, etc.; as for the structure of the mold, when it is taken out, it can be solid or it can have a cavity structure; when it is not taken out, the mold preferably has a cavity structure with an upper part that can be opened ;
  • the size of the mold can be adjusted according to the size of the pre-stored objects, and the present invention has no special limitations.
  • the "and/or" involved in the present invention means that one of the two conditions before and after "and/or" can be selected, or the two conditions can coexist.
  • phase change materials Real-time monitoring of the temperature of phase change materials is also very important. For example, most vaccines, including the COVID-19 vaccine, must be kept below 8°C during transportation and storage. Therefore, real-time temperature monitoring of each vaccine is required. Organic phase change materials also need to consider reprocessability and recyclability to avoid environmental pollution and resource waste.
  • the eighth aspect of the present invention is to provide a device with real-time temperature monitoring Functional recyclable cold storage phase change material
  • the recyclable cold storage phase change material has a layer structure, including those prepared by the recyclable cold storage phase change composite material described in the sixth aspect or the preparation method described in the seventh aspect
  • the inner layer is formed of a recyclable cold storage phase change composite material
  • the outer layer is formed of a second polymer aerogel.
  • the thickness of the inner layer and the thickness of the outer layer can be selected within a wide range.
  • the thickness of the inner layer is 3 mm or more, and the thickness of the outer layer The thickness is more than 5mm.
  • the present invention there is a spacer layer between the inner layer and the outer layer.
  • the present invention has no special restrictions on the material selection of the spacer layer, as long as the phase change material can be separated between the internal encapsulated aerogel and the external thermal insulation aerogel to avoid mutual penetration. Including but not limited to metal (such as thin aluminum foil), plastic, etc.
  • the thickness of the above inner layer can be controlled according to the distance between the four walls of the mold or the distance between the four walls and the bottom and the spacer layer during the preparation process.
  • the thickness of the outer layer can be controlled according to the distance between the surrounding layer and the outer container wall.
  • the above recyclable cold storage phase change material can be cylindrical with a radial layer structure, the outer layer is a second polymer aerogel, the inner layer is a recyclable cold storage phase change composite material, and a spacer layer is provided between the two layers; or the above can be
  • the recycled cold storage phase change material can be a flat plate with a layer structure, with a spacer layer in the middle.
  • One side of the spacer layer is the outer layer of the second polymer aerogel, and the other side is the inner layer of the recyclable cold storage phase change composite material;
  • the outermost part of the recyclable cold storage phase change material is also wrapped with a packaging material.
  • the shape and structure of the spacer layer can be cylindrical or flat, as long as it can cover the inner layer of aerogel and isolate the inner and outer layers.
  • the inner layer is provided with a cavity; the cavity comes from the mold itself or a cavity formed after removing the mold.
  • refrigerated objects such as vaccines, medicines, etc.
  • the cavity comes from the mold itself or a cavity formed after removing the mold.
  • refrigerated objects can also be placed in the cavity, so that the cold storage environment of the refrigerated objects is more uniform and the preservation effect is better.
  • the second polymer aerogel can be selected within a wide range.
  • the second polymer aerogel has photoluminescence properties (ie, fluorescence properties) and can change with temperature. Change The optical signal changes.
  • the optical signal here refers to the peak position and/or intensity of the fluorescence spectrum.
  • the second polymer aerogel is selected from the recyclable cold storage phase change composite material according to the sixth aspect and has photoluminescence properties (ie, fluorescence properties) and can At least one polymer aerogel whose light signal changes as the temperature changes; and the second polymer aerogel and the polymer aerogel in the recyclable cold storage phase change composite material can be the same or different .
  • the second polymer is styrene maleic anhydride maleimide copolymer aerogel (that is, it includes maleic anhydride, maleimide, maleic acid and ammonium salt, maleamide A copolymer formed by one or more polymerized monomers of acids and ammonium salts and styrene).
  • the inventor of the present invention found that the styrene maleic anhydride maleimide copolymer aerogel has the ability to follow the Changes in temperature change the optical signal and the fluorescence properties.
  • the phase change cold storage material of the present invention is characterized in that the inner layer is the airgel phase change composite material described in the sixth aspect, and the outer layer is the airgel phase change composite material described in the sixth aspect.
  • the polymer aerogel used in the airgel phase change composite material preferably has a photoluminescence effect (for example, it can be a styrene maleic anhydride/maleimide copolymer aerogel) , and the intensity changes with temperature (for example, increases as the temperature decreases). Therefore, the temperature of the phase change material can be determined by measuring the fluorescence intensity, and real-time temperature monitoring of the cold storage material can be achieved.
  • a ninth aspect of the present invention provides a method for preparing a recyclable cold storage phase change material with real-time temperature monitoring function as described in the eighth aspect, which is characterized by comprising the following steps:
  • step (3) Heat-treat the water-soluble polymer obtained in step (2), and optionally take out the mold to obtain a polymer aerogel with cavities;
  • step (2) step (3), step (4) and/or between steps and/or after step (4), the second polymer aerogel is coated on the outside of the spacer layer, thereby forming the The outer layer of the recyclable cold storage phase change material;
  • step (2) the aqueous solution containing the second polymer aerogel and/or the second polymer aqueous solution is placed in the space outside the spacer layer, thereby forming the outer layer of the recyclable cold storage phase change material; preferably, the third
  • the two polymer aqueous solutions are the same as the polymer aqueous solutions in step (1);
  • step (2) is preferably carried out in the following manner:
  • the polymer aqueous solution is placed in the space outside the spacer layer, the space inside the spacer layer, or the space between the inside of the spacer layer and the mold, to obtain a water-soluble polymer with a layer structure.
  • the preparation method of the recyclable cold storage phase change material with real-time temperature monitoring function of the present invention includes the preparation process of polymer aerogel.
  • the polymer aerogel (recyclable polymer aerosol) described above can be used.
  • the preparation method of the gel) obtains the polymer aerogel located in the spacer layer, and at the same time, during the preparation process of the inner polymer aerogel, the second polymer aerogel or the second polymer aerogel containing the second polymer aerogel is The aqueous solution and/or the second polymer aqueous solution are coated outside the spacer layer.
  • the second polymer aerogel or the aqueous solution containing the second polymer aerogel and/or the second polymer aqueous solution outside the spacer layer it can be based on the type of the second polymer aerogel selected. Make your selection. For example, when the second polymer aerogel is the polymer aerogel described above (that is, the same type as the polymer aerogel of the inner layer), you can choose to replace the second polymer aerogel in step (1) in step (2).
  • the water-soluble polymer is arranged outside the spacer layer, and then subsequent processing steps are performed, so that after the processing step of step (3), both the inside and outside of the spacer layer are recyclable polymer aerogels; if the second polymer aerosol
  • the gel (or precursor) does not need to be freeze-dried but requires heat treatment.
  • the second polymer aerogel (or precursor) can also be arranged outside the spacer layer in step (2); the second polymer aerogel (or precursor) When heat treatment is not required, the second polymer aerogel product can also be placed outside the spacer layer after step (3) or step (4) or step (4). In short, based on the principle of program or process saving, it can be flexibly adjusted according to the type of the second polymer aerogel.
  • the amount of airgel raw material used in the inner layer and the outer layer can be selected within a wide range.
  • the amount is used so that the thickness of the inner layer in the finished product is 3 mm or more, and the thickness of the outer layer is 5 mm or more. .
  • the selection of materials of the second polymer aerogel or (precursor) For the selection of materials of the second polymer aerogel or (precursor), the selection of phase change materials, the dosage, etc., the selection of materials of the second polymer aerogel or (precursor) described in the eighth aspect can be used. The selection and dosage of phase change materials will not be described in detail here.
  • the mass fraction of the polymer content in the polymer aqueous solution of the inner layer is 0.1%-30%, preferably 1%-10%, more preferably 2%-5%, and/or , the mass fraction of the second polymer content in the aqueous solution of the second polymer aerogel and/or the second polymer aqueous solution is each 0.1%-30%, preferably 0.5%-10%, more preferably 1%-5%.
  • the polymer aqueous solution obtained in step (1) has different cold source temperatures in all directions, preferably one-way cold source temperatures. In this way, an anisotropic aerogel can be obtained, and in this preferred embodiment, the leakage of the resulting cold storage material is lower.
  • Pre-freezing containers can be of any shape and size and can be customized to the shape of the desired aerogel or refrigerated item. Freezing can use cold sources such as refrigerators, or liquid nitrogen can be used for freezing. In this step, if the cold source temperature is consistent in all directions of the mold, the aerogel prepared is isotropic; if the cold source temperature in all directions of the pre-freezing container is different, anisotropic aerogel can be prepared, and anisotropic aerogel is preferred in the present invention. Glue, more preferably anisotropic aerogels with different unidirectional cold source temperatures.
  • the specific conditions in the above steps (1), (2), and (3) can be selected within a wide range, and preferably the preferred conditions in the above-mentioned preparation method for preparing polymer aerogels can be adopted.
  • the heat treatment temperature in step (3) is 100-300°C, preferably 120-220°C, more preferably 160-200°C; the heat treatment time is 0.1-10 hours, preferably 0.5-3 hours, more preferably 1-2 hours.
  • Glue recycling methods can use the following methods:
  • the recycling method includes mixing and reacting the polymer aerogel and/or the material containing the polymer aerogel with ammonia water under closed conditions until an aqueous solution containing the recycled polymer is obtained, optionally removing insoluble matter, An aqueous solution of recovered polymer was obtained.
  • This airgel recycling method does not require the introduction of organic solvents, and does not require high-temperature and high-pressure stirring. It only requires a certain concentration of ammonia water, preferably kept below 100 degrees Celsius, and can achieve rapid and efficient recycling. This method has low energy consumption, little pollution, high efficiency, and the recovered The polymer solution can again be used in the preparation of polymer aerogels.
  • the recycling method of the polymer aerogel of the present invention is as follows: placing the polymer aerogel in a certain concentration of ammonia water, placing it in a closed container, heating it at a certain temperature, and waiting until it is completely dissolved to obtain an aqueous solution of the copolymer. .
  • the conditions of the mixing reaction in the recovery method can be selected within a wide range.
  • the temperature of the mixing reaction is 0-200°C, preferably 50-150°C, and more preferably The temperature is 80-100°C, and/or the mixing reaction time is 0.01-100h, preferably 0.5-10h, more preferably 1-5h.
  • the recovery method also includes freeze-drying and heat-treating the aqueous solution of the recovered polymer to recover the polymer aerogel; preferably, the freeze-drying conditions include: the temperature is -10 °C or lower, it may be -20°C or lower, or it may be -30°C or lower, and/or the vacuum degree is 1000Pa or lower, it may be 100Pa or lower, or it may be 10Pa or lower.
  • the conditions for heat treatment can be selected within a wide range.
  • the conditions for heat treatment include:
  • the temperature is 100-300°C, preferably 130-200°C, more preferably 150-190°C and/or, and the time is 0.1-10h, preferably 0.5-3h, more preferably 1-2h.
  • the above method can be used to convert the recyclable cold storage phase change material into Phase change composite materials may be used to process the inner layer of recyclable cold storage phase change composite materials with real-time temperature monitoring function in ammonia water to remove the polymer. Separate from the phase change material and then undergo post-processing steps to obtain a recyclable polymer aerogel, or continue to use the preparation method of a recyclable cold storage phase change composite material or a recyclable cold storage phase change material with real-time temperature monitoring function to obtain The recyclable cold storage phase change composite material in the present invention or the recyclable cold storage phase change material with real-time temperature monitoring function.
  • the second polymer aerogel is the recyclable polymer aerogel of the present invention (the polymer in the polymer aerogel contains maleic anhydride groups and maleimide groups),
  • the above method can be used to recycle the material of the inner layer together.
  • the second polymer aerogel is a different kind of polymer aerogel, the outer layer of the recyclable cold storage phase change material with real-time temperature monitoring function can be recycled.
  • the two-polymer aerogel is peeled off and then subjected to subsequent recycling steps.
  • a tenth aspect of the present invention is to provide a recyclable cold storage phase change composite material described in the sixth aspect or a recyclable cold storage phase change composite material prepared by the preparation method described in the seventh aspect.
  • the eighth aspect The recyclable cold storage phase change material with real-time temperature monitoring function or the recyclable cold storage phase change material with real-time temperature monitoring function prepared by the preparation method described in the ninth aspect is useful in the fields of food preservation and cold chain transportation. application.
  • the present invention provides a recyclable polymer aerogel and its preparation method, recycling method and application.
  • the invention also provides a recyclable cold storage phase change composite material, a recyclable airgel phase change cold storage material with real-time temperature monitoring function, and a preparation method and application thereof.
  • the present invention has the following advantages:
  • the polymer aerogel of the present invention does not need to undergo cross-linking or hydrophobization treatment, that is, it has the characteristics of super lipophilicity and hydrophobicity, does not require any treatment, and can be directly used as an oil-water separation material; the polymer aerogel of the present invention It can also be recycled in a convenient and environmentally friendly way, with a recycling efficiency that can be higher than 99%.
  • the airgel preparation and recycling process does not require the use of any organic solvents, and is low-energy, high-efficiency, green and environmentally friendly.
  • the polymer aerogel of the present invention has low thermal conductivity, low density, and good heat resistance. It can be used in a variety of fields and has extremely high application value.
  • the present invention prepares maleimide-based polymers into gas Gel, which broadens the application range of copolymers containing maleic anhydride and maleimide groups.
  • the recyclable cold storage phase change composite material in the present invention includes a polymer aerogel and a phase change material loaded in the polymer aerogel; wherein, the polymer in the polymer aerogel contains Structural units containing maleic anhydride groups and structural units containing maleimide groups.
  • the polymer aerogel can be recycled in ammonia water, and the recycled polymer aerogel obtained through post-processing (including heat treatment) can be reused. Based on this, the recyclable cold storage phase change composite material in the present invention can Recycle over and over again.
  • the recyclable cold storage phase change composite material in the present invention is not only recyclable, but also has strong cold storage performance, less leakage of the phase change material, can maintain low temperatures for a long time, and can be widely used in the fields of food preservation and cold chain transportation. (such as cold chain transportation of vaccines and drugs) and other links.
  • the recyclable cold storage phase change material with real-time temperature monitoring function in the present invention has a sandwich structure, including an inner layer formed of a recyclable cold storage phase change composite material, and an outer layer formed of a second polymer aerogel.
  • the preferred second polymer aerogel has photoluminescence properties and can change the light signal as the temperature changes, better temperature monitoring can be achieved, so that both Enable high-volume temperature monitoring and recyclability performance.
  • Figure 1 is the Fourier transform infrared spectrum test curve of the aerogel recovered from Comparative Example 3A, Example 1A and Example 1A;
  • Figure 2 is a hydrogen nuclear magnetic resonance spectrum curve of the airgel recovered in Example 1A and Example 1A;
  • the absorption peak at 935cm -1 is the characteristic absorption peak of COC in the five-membered anhydride ring, while the absorption peak at 1349cm -1 belongs to the unique CN stretching vibration peak of the imide ring.
  • the chemical shifts of the five hydrogens on the benzene ring are between 7.7 and 6.0 ppm, and the chemical shifts of the hydrogen on the NH of maleimide are between 10.2 and 9.4 ppm. between.
  • the ratio between maleimide and maleic anhydride (maleic anhydride in the polymer raw material is equal to the polymer gas
  • the ratio of the total amount of maleic anhydride + maleimide in the gel ie, the maleimidation rate.
  • Figure 3 is a scanning electron microscope photograph of the pore structure of the airgel obtained in Example 1A, which can prove the existence of the porous structure of the airgel.
  • Figure 4 is the temperature rise curve of the cold storage phase change material obtained in Example 1B;
  • Figure 5 is the emission spectrum of the maleimide-based aerogel in the outer layer of the phase change cold storage material prepared in Example 1B at an excitation wavelength of 400 nm.
  • Figure 5 shows that through the fluorescence-temperature relationship of the surface aerogel, the temperature of the phase change material can be monitored in real time.
  • FIG. 6 is a schematic diagram of the appearance of the recyclable cold storage phase change composite material (a), the recycled phase change material (b) and the recycled polymer aerogel (c) in Example B. It can be seen that the recyclable cold storage phase change composite material in the present invention can be recycled;
  • Figure 7 is a schematic three-dimensional structural diagram of the airgel phase change thermal storage material with real-time temperature monitoring function obtained in Example 1B;
  • Figure 8 is a schematic longitudinal cross-sectional structural diagram of the airgel phase change thermal storage material with real-time temperature monitoring function obtained in Example 1B.
  • the water contact angle of the product obtained in the example was measured using the German EASYDROP contact angle tester: Use a thin blade to cut the polymer airgel into thin slices of about 10*10* 2mm3 , and fix the airgel sheet on the operating table. , keep the sample flat in the horizontal direction during the fixation process, and then place the slide on the sample stage of the EASYDROP contact angle measuring instrument for fixation. Adjust the control volume of the instrument to 4 ⁇ 0.02 ⁇ L and drip the water droplets into the center of the sample. After 1 min on the surface of the airgel, start measuring the angle at the three-phase junction from the solid-liquid interface through the inside of the droplet to the vapor-liquid interface, which is the water static contact angle (referred to as the water contact angle).
  • TC3100 model universal thermal conductivity meter produced by Xi'an Xiaxi Electronic Technology Co., Ltd. First, cut the airgel into slices of about 30*20* 5mm3 with a thin blade, cover both sides of the test probe with two airgel slices, use weights to compress it, adjust the test temperature to 25 degrees Celsius, and set The test method is to test insulation material samples, and the thermal conductivity obtained from the test results is the average of at least 5 measurement results.
  • the aerogels in the examples were tested using an IS5 Fourier transform infrared spectrometer from Nicolet in the United States. Collect the infrared spectrum of the sample by pressing it with KBr. Take an appropriate amount of aerogel, grind it with KBr, and test after pressing. The number of scans is set to 32, the range of spectrum collection is 400-4000cm, and the optical frequency is 1cm -1 .
  • the 400-MR DD2 nuclear magnetic resonance spectrometer of the American Agilent Company was used to analyze the gas condensation in the examples. Glue samples were subjected to 1 H NMR testing. Among them, dimethyl sulfoxide-d6 is used as the solvent for water-soluble aerogels, acetone-d6 is used as the solvent for hydrophobic and water-resistant aerogels, and tetramethylsilane (TMS) is used as the internal reference reagent.
  • TMS tetramethylsilane
  • Airgel pore structure testing method
  • the pore structure of the aerogel sample in the example was observed using an EM30AX scanning electron microscope of COXEM Company of South Korea. First, the surface of the sample to be tested is coated with gold, and then the coated sample is placed on the scanning electron microscope detection stage, and the area on the sample is scanned with a scanning electron microscope to obtain a photo of the pore structure.
  • Thermogravimetric analysis (TGA, Mettler Toledo, Switzerland) was used to determine the thermal stability of the sample, and 5 mg of aerogel was taken for testing. The test was conducted under nitrogen flow, with a heating rate of 20°C/min and a temperature range from 50°C to 550°C.
  • the glass transition temperature of the samples was measured using a Perkin-Elmer pyris -1 differential scanning calorimeter (DSC), calibrated using indium and zinc standards. 5-6mg sample from the injection rod was heated from 150°C to 300°C under nitrogen flow and held at 300°C for 3 minutes. Next, the sample was cooled to 150°C for 1 min and heated again to 300°C. All heating and cooling processes are programmed at a speed of 10°C/min. The glass transition temperature (Tg) was determined based on the relevant peaks in the DSC curve.
  • DSC Perkin-Elmer pyris -1 differential scanning calorimeter
  • the leakage amount is: m/15*100wt %. If the sample is completely melted and cannot be removed, the leakage amount is 100wt%.
  • the test instrument for the fluorescence spectrum of the above-mentioned nano-fluorescent elastic particles is: F-7000 FLSpectrophotometer, the test method is Wavelength scan, the excitation wavelength is set to 400nm, and the emission spectrum is measured.
  • Thermal properties of aerogels and phase change materials were measured using differential scanning calorimetry (DSC) using a Perkin-Elmer pyris-1 calibrated with indium and zinc standards.
  • DSC differential scanning calorimetry
  • the samples were heated from 20 to 150°C under nitrogen flow and held at 20°C and 150°C for 5 min respectively.
  • phase change materials the samples were heated from 50°C to 300°C under nitrogen flow and stored at 50°C and 300°C for 5 min respectively. All heating and cooling processes are programmed at a speed of 20°C/min.
  • the latent heat of melting ⁇ Hm and the latent heat of solidification ⁇ Hf as well as the melting temperature Tm and solidification temperature Tf are determined according to the relevant peaks of the DSC curve.
  • the water-soluble polymer is placed in a constant-temperature container and heat-treated at 180°C for 2 hours to obtain maleimide-based aerogel (ie, the polymer aerogel in the present invention) through dehydration and deamination.
  • Example 1A 91.5g of water and 3.5g of 25% ammonia water with a mass fraction of 91.5g were replaced with 94g of water and 1g of sodium hydroxide.
  • the other preparation steps were the same as in Example 1A.
  • Example 1A 91.5g of water and 3.5g of 25% ammonia with a mass fraction of 91.5g were replaced with 94g of water and 2g of sodium hydroxide, and other preparation steps were the same as in Example 1A.
  • Example 1A The heat treatment process in Example 1A is not performed, and other preparation steps are the same as Example 1A.
  • Example 1A The maleic anhydride in the maleic anhydride-styrene copolymer in Example 1A was replaced with azophenyl maleimide, and other preparation steps were the same as in Example 1A.
  • Example 1A Change the 91.5g water, 3.5g mass fraction of 25% ammonia water and 5g maleic anhydride-styrene copolymer in Example 1A into 94.9g water, 2.1g 25% ammonia water and 3g maleic anhydride styrene copolymer, and others
  • the preparation steps are the same as in Example 1A.
  • Example 1A The 5 g of maleic anhydride-styrene copolymer in Example 1A was changed into 5 g of maleic anhydride isobutylene copolymer (Kuraray ISOBAM-08), and other preparation steps were the same as in Example 1A.
  • Example 1A The 5 g of maleic anhydride-styrene copolymer in Example 1A was changed into 5 g of the polymer obtained in Preparation Example 3A. The other preparation steps were the same as in Example 1A.
  • Example 1A The maleic anhydride copolymer in Example 1A was replaced with the styrene maleic anhydride vinyl silicone oil copolymer in Preparation Example 2A, and other preparation steps were the same as in Example 1A.
  • Example 5A instead of adding 3.5g of 25% ammonia water with a mass fraction of 3.5g of water, the glass bottle was replaced with a reaction kettle with a polytetrafluoroethylene inner tank, and the oven temperature was changed from 95°C to maintain 150°C. The holding time at 95°C in the oven was changed from 4h to 12h. A uniform 5% mass fraction polymer solution was taken out and the heat treatment temperature was changed to 130°C. The remaining steps were the same as in Example 5A.
  • Example 5A According to the method of Example 5A, the addition of 3.5g mass fraction of 25% ammonia water and 91.5g water was replaced with the addition of 40g mass fraction of 25% ammonia water and 55g water, and the oven temperature in which the glass bottle was placed was changed from 95°C. In order to maintain 20°C, the holding time was changed from 4h to 0.5h, the heat treatment temperature in Example 1A was changed to 200°C, and the remaining steps were the same as in Example 5A.
  • the water-resistant maleimide-based aerogel of the present invention is weighed to obtain mass m 1 , and 91.5g of water is added to a sealed glass bottle with a lid, and then 3.5g of 25% ammonia water with a mass fraction of 25% are added, and 5g ( That is, add m 1 ) water-resistant maleimide aerogel into the bottle, tighten the lid of the sealed glass bottle and place it in an oven to keep at 95°C for 2 hours to obtain a uniform recycled polymer solution.
  • Recycle the water-soluble polymer put the recycled water-soluble polymer into a constant temperature container and perform heat treatment at 180°C for 2 hours to obtain the recycled water-resistant maleimide-based aerogel (i.e. the recycled polymer gas in the present invention) through dehydration and deamination. gel).
  • the recycled water-resistant maleimide-based aerogel i.e. the recycled polymer gas in the present invention
  • the mass of the recovered water-resistant maleimide-based aerogel is called m 2 , and the recovery efficiency is m 2 /m 1 *100%.
  • Example 1A (Recycling 1)
  • Example 1A (Recovery 1)
  • Example 1A of the present invention has good heat resistance, with a glass transition temperature near 250°C and a decomposition temperature around 300°C.
  • the heat resistance of the airgel prepared by recycling the polymer is higher than that before recycling, which proves that the polymer has good heat resistance before and after the airgel is recycled, and the recycling process is green and environmentally friendly.
  • the water solubility test results of the aerogels prepared in Examples 1A-6A and Comparative Examples 1A-4A are listed in Table 1A.
  • the spectral test curve is shown in Figure 1
  • the nuclear magnetic test of the Example and the Comparative Example is shown in Figure 2
  • the scanning electron microscope photo of the pore structure of the airgel obtained in Example 1A is shown in Figure 3. From the aerogel infrared spectrum test curve in Figure 1 and the aerogel NMR hydrogen spectrum curve in Figure 2, it can be determined that there is a maleimide structure in the polymer aerogel structure.
  • the maleimidation rate in Table 2A is based on the total molar amount of structural units containing maleic anhydride groups and structural units containing maleimide groups in the polymer aerogel being 100%. Calculated, the molar ratio of the structural units containing maleimide groups.
  • polymer preparation place 500ml isoamyl acetate in a 1000ml three-necked flask, Blow in nitrogen for 30 minutes to remove oxygen, and add 24.5g maleic anhydride and 26g styrene into the flask. After it is completely dissolved, add 0.4g of azobisisobutyronitrile, raise the temperature of the water bath to 70°C, and react for 7 hours.
  • the bottom of the spacer layer is about 5mm away from the beaker, and place it Freeze in a -30°C refrigerator for 2 hours, transfer the frozen sample to a freeze dryer (below -30°C, 10 Pa or less) and freeze-dry for 72 hours, then take out the obtained water-soluble polymer.
  • the water-soluble polymer is placed in an oven for heat treatment at 180°C for 2 hours to dehydrate and deaminate the maleimide-based polymer aerogel (ie, the polymer aerogel in the present invention) in both the inner and outer layers.
  • the maleimide-based polymer aerogel ie, the polymer aerogel in the present invention
  • vaccines, etc. When used, vaccines, etc. can be placed in glass bottles.
  • the bottom of the spacer layer is about 5mm away from the beaker, place it in a -30°C refrigerator for 2 hours, transfer the frozen sample to a freeze dryer (below -30°C, below 10Pa) and freeze-dry for 72 hours, then take out the obtained water-soluble sample sex polymer.
  • the water-soluble polymer is placed in an oven for heat treatment at 180°C for 2 hours, and dehydration and deamination are used to obtain maleimide polymer aerogels in both the inner and outer layers, and the maleimide polymer aerogel in the inner layer is Anisotropic aerogels.
  • Example 1B the steps in the preparation process of the polymer solution were changed to: add 94.9g of water into a glass bottle with a lid, then add 2.1g of 25% ammonia water and 3g of maleic anhydride-styrene co- Polymer, tighten the cap of the glass bottle and place it in an oven to maintain 95°C. After 4 hours, take it out to obtain a uniform 3% mass fraction polymer solution.
  • Other preparation steps are the same as in Example 1B, where the amount of dodecane added is 11ml.
  • Example 2B Dodecane in Example 2B was replaced with tetradecane, and other preparation steps were the same as in Example 2B.
  • the pre-freezing After the pre-freezing is completed, put it into a freeze dryer (below -30°C, below 10Pa) and freeze dry for 72 hours to obtain anisotropic water-soluble polymer. Place the water-soluble polymer in an oven for heat treatment at 130°C After 2 hours, the maleimide polymer aerogel was obtained by dehydration and deamination. Inject 11 ml of dodecane phase change material into the inner layer of airgel until it is filled with excess phase change material. Invert and wipe the surface of the airgel phase change composite material to obtain a maleimide copolymer airgel phase change material. Cold storage materials.
  • Example 2B The 15 ml polymer solution in Example 2B was replaced with the above-mentioned 5% copolymer solution in this example, and other preparation steps were the same as in Example 2B.
  • the maleimide polymer aerogel obtained by dehydration and deamination was tested, and then the phase change material was injected according to the steps of Example 2B.
  • the leakage amount, phase change temperature and phase change latent heat tested on the phase change material are close to those in Example 2B.
  • phase change material was used as a raw material for preparing phase change materials.
  • a phase change composite material was prepared according to the method of Example 2B.
  • the adsorption capacity of the phase change material is relatively high, and the leakage amount of the phase change material is less. It can be widely used in the fields of food preservation and cold chain transportation ( For example, cold chain transportation of vaccines and drugs) and other links.
  • the porous aerogel in the present invention causes very little latent heat loss to phase change materials, and can prepare phase change composite materials with high cold storage capacity and low leakage.
  • any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas formed thereby are regarded as part of the original disclosure or original record of the present invention and shall not It should be regarded as new content that has not been disclosed or expected herein, unless those skilled in the art believe that the combination is obviously unreasonable.

Abstract

本发明涉及多孔材料领域，具体是涉及一种可回收聚合物气凝胶及其制备方法、回收方法和应用；以及一种包含所述可回收聚合物气凝胶的可回收蓄冷相变复合材料、具有实时温度监测功能的可回收蓄冷相变材料及其制备方法和应用。该聚合物气凝胶的聚合物中含有含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元。本发明首次将含有含马来酰亚胺基的结构单元的聚合物制备成气凝胶，拓宽了含有马来酸酐基、马来酰亚胺基的共聚物的应用范围；另外，本发明的所制备的气凝胶具有极高的回收效率，在使用氨水溶解回收后，回收效率可高于99％，气凝胶制备回收过程无需使用任何有机溶剂，具有低能高效、绿色环保的特点。该可回收蓄冷相变复合材料既可回收，泄漏量更少，还能够保持长时间的低温；该具有实时温度监测功能的可回收蓄冷相变材料具有层结构，包括可回收蓄冷相变复合材料形成的内层，和第二聚合物气凝胶形成的外层，可以同时实现大批量温度监控和可回收性能。

Description

可回收聚合物气凝胶、蓄冷相变复合材料及制法和应用 技术领域
本发明涉及多孔材料领域，具体是涉及一种可回收聚合物气凝胶及其制备方法、回收方法和应用；以及一种包含所述可回收聚合物气凝胶的可回收蓄冷相变复合材料、具有实时温度监测功能的可回收蓄冷相变材料及其制备方法和应用。
背景技术
聚合物气凝胶是指一种由胶体粒子或高聚物分子互相团簇而成的、具有三维多孔结构，同时气体分散介质填充于网状孔隙里的轻质固体新材料，具有密度低、孔隙率高、比表面积大的特点。它们还具有耐高温、低导热性和低折射率等特性。目前已广泛应用于隔热隔声材料，吸附分离，催化、能量储存和转化、吸声和隔音，传感器平台，防污、防黏材料，防水织物，质子交换膜等。
聚合物气凝胶通常采用溶胶-凝胶法、相分离法制备。溶胶-凝胶法需要至少包括溶液-溶胶转化、溶胶-凝胶转化、凝胶-气凝胶转化三个过程，需要多达6-7天的老化处理，耗时极长。相分离法可以先采用有机溶剂制成高分子溶液，凝胶化后再用水置换出有机溶剂制成水凝胶，进而制成气凝胶，该方法的不足之处是必须处理大量有机溶剂。亦可采用水溶液直接制备聚合物气凝胶，但必须对气凝胶产品进行交联和疏水后处理，过程较为复杂。显而易见，聚合物气凝胶，特别是交联低密度聚合物气凝胶，不仅制备过程会带来环境污染，制品也难以回收利用。因此，随着消费量的提高，聚合物气凝胶会产生比普通塑料制品更严重的“白色污染”问题，这制约了聚合物气凝胶的工业化应用。显然，开发低污染可回收利用的聚合物气凝胶是气凝胶技术中亟待解决的技术问题。
现有技术中制备的聚合物气凝胶为实现疏水耐水效果，往往需要进行交联和疏水化处理，所制备的交联气凝胶极难回收。所以制备出无需交联的疏水 耐水气凝胶是实现气凝胶可回收的最佳方法，但通常情况下疏水气凝胶制备回收过程中，需要使用大量有机溶剂，这又带来了新的污染。
近年来，对冷能的需求快速增长，使得低温储能极具吸引力。常用的制冷方式有两种：一种是主动式制冷，如利用电能的冷藏冷冻设备，如冰箱或冰柜；另一种是被动制冷，如利用蓄冷相变材料来制冷的冷藏箱、冷藏袋、冰盒等。冰箱等主动式制冷方式成本较高，控制和减少消耗以及提高系统效率已成为该主题研究人员的首要任务之一，而冷藏箱和相变材料等被动制冷方式，可利用夜间“低谷”电能或太阳能等绿色电能来蓄冷，是极有潜力的发展方向。在众多的储能技术中，利用基于相变材料的固-液转变来存储大量能量的方法已在各种冷应用中进行，如食品储存、运输和空调等。相变材料具有较高的能量存储密度，提供了一种紧凑且可行的解决方案来解决供需失衡的问题。相变材料主要分为有机和无机相变材料，与无机相变材料相比，有机相变材料因其无毒、轻微过冷和良好的循环稳定性等优点在实际应用中受到更多关注。然而，有机相变材料在直接用作储能材料时会遇到泄漏的风险，对相变材料进行封装以防止泄漏问题是非常必要的。此外，有机相变材料还需要考虑可再加工性和可回收性，避免其造成环境污染和资源浪费。
因此，如何提供一种既具有疏水耐水效果又能够方便环保地实现回收利用的疏水气凝胶，以及如何在上述气凝胶的基础上提供一种泄漏量低同时又可以回收的可回收蓄冷相变复合材料，是目前需要解决的技术难题。
发明内容
针对现有技术中存在的技术问题，本发明提供了一种可回收聚合物气凝胶及其制备方法、回收方法和应用，首次将含有含马来酰亚胺基的结构单元的聚合物制备成气凝胶，拓宽了含有含马来酸酐基、马来酰亚胺基的结构单元的共聚物的应用范围；更重要的是，本发明的所制备的气凝胶具有极高的回收效率，在使用氨水溶解回收后，回收效率可高于99％，气凝胶制备回收过程无需 使用任何有机溶剂，具有低能高效、绿色环保的特点。不仅如此，本发明的聚合物气凝胶具有很好的疏水耐水性能，同时，导热系数低、密度小、耐热性较好，能够用于多种领域，具有极高的应用价值。
本发明发明人在研究中发现，当将具有马来酸酐及其衍生基团的共聚物如含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料溶解于氨水中，能够得到聚合物水溶液。冷冻干燥后，再通过热处理制备出具有疏水耐水性能的含有马来酸酐基团和马来酰亚胺基团的共聚物气凝胶。由于马来酸及其铵盐、马来酰胺酸及其铵盐、马来酸酐和马来酰亚胺的官能团之间具有很强的氢键作用，因此热处理过程中气凝胶的三维孔结构得以保持稳定，在不需要进行交联和疏水化处理的条件下得到疏水耐水的聚合物气凝胶，绿色环保且降低了制备的时间和材料成本。采用本发明的方法制备的聚合物气凝胶可以在氨水的作用下进行回收，利用这类聚合物的特殊性能可以实现水溶性聚合物和耐水性疏水气凝胶的反复转化，上述过程不需要使用有机溶剂，更加绿色环保。
在上述可回收聚合物气凝胶的基础上，本发明还提供了一种可回收蓄冷相变复合材料及其制备方法和应用，该可回收蓄冷相变复合材料不仅具有蓄冷能力，而且可以回收循环利用，同时，又具有泄漏量低的特点。在此基础上，本发明又提供了一种具有实时温度监测功能的可回收蓄冷相变复合材料，其不仅具有蓄冷能力、可回收、泄漏量低，而且还具有实时温度监测功能。
本发明的第一个方面是提供一种聚合物气凝胶，所述聚合物中含有含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元。
根据本发明，马来酸酐基团指的是马来酰亚胺基团 指的是
根据本发明，所述聚合物是碳链聚合物，其中杂原子O和N存在于侧基中。
在本发明一种优选的实施方式中，以含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元的总摩尔量为100％计，所述聚合物中含马来酰亚胺基团的结构单元的摩尔比例为5％-70％，优选为10％-60％；更优选为20％-50％，例如20％、25％、30％、35％、40％、45％、50％，以及任意两数值或者任意两数值的任意区间。
根据本发明，所述聚合物可以在较宽的范围内选择，在本发明一种优选的实施方式中，所述聚合物衍生自含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料。
马来酸酐基团指的是马来酰亚胺基团指的是马来酸及铵盐基团、马来酰胺酸及铵盐基团指的是式中M相同或不同，各自为羟基或氨基或铵(-ONH4)。
根据本发明，所述聚合物是碳链聚合物，其中杂原子O和N存在于侧基中。
本发明中，所述聚合物原料包括但不限于包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共 聚物；例如，当所述聚合物原料为诸如苯乙烯马来酸酐乙烯基硅油共聚物时，也可以实现本发明。以上包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共聚物具有更低的原料成本。
优选地，所述聚合物原料为包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共聚物；更优选地，所述烯烃单体为α-甲基苯乙烯、苯乙烯、异丁烯、醋酸乙烯酯中的至少一种。更优选地，所述聚合物原料为包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与α-甲基苯乙烯、苯乙烯、异丁烯中的一种的交替共聚物。
作为举例，本发明中所述聚合物原料包括但不限于苯乙烯马来酸酐共聚物、苯乙烯马来酸酐乙烯基硅油共聚物、马来酸酐异丁烯共聚物中的至少一种。优选地，本发明中所述聚合物原料包括苯乙烯马来酸酐共聚物、马来酸酐异丁烯共聚物中的至少一种。
在本发明一种优选的实施方式中，所述聚合物气凝胶能够溶于0-150℃的氨水中，形成聚合物水溶液；优选地，所述聚合物水溶液经预冷冻、冷冻干燥、热处理，能够回收得到聚合物气凝胶。基于此，本发明的聚合物气凝胶能够方便环保地实现回收利用。
在本发明一种优选的实施方式中，所述聚合物气凝胶的导热系数为0.025-0.05W/(m·k)，优选为0.027-0.04W/(m·k)。本发明所述的聚合物气凝胶具有低热导率的特点，无需进行任何处理，可直接作为保温材料使用。
在本发明一种优选的实施方式中，所述聚合物气凝胶的密度为10-100kg/m3，优选为15-75kg/m3具体地，例如，15kg/m3、35kg/m3、45kg/m3、55kg/m3、65kg/m3、75kg/m3，以及任意两数值或者任意两数值的任意区间；和/或，所述聚合物气凝胶为多孔材料。本发明所述的聚合物气凝胶孔隙率高，是一种三维多孔材料，可以作为载体使用。例如作为骨架负载有机相变材料， 避免相变材料的泄漏，所制备的相变复合材料亦可通过氨水进行回收。
本发明的发明人研究发现，所述聚合物气凝胶在为苯乙烯马来酸酐马来酰亚胺共聚物气凝胶时，还具有光致发光性能且能够随着温度的变化光信号发生变化。还可以利用本发明中的该类所聚合物气凝胶的光致发光性能作为显示温度变化的指示材料。
在本发明一种优选的实施方式中，所述聚合物气凝胶的静态水接触角在100°以上，优选110°以上，更优选在135°以上。
在本发明一种优选的实施方式中，所述聚合物气凝胶不溶于水，优选将所述聚合物气凝胶置于20-40℃水中浸泡24h，优选浸泡72h，更优选浸泡168h后，不会溶解形成聚合物的水溶液。本发明所述的聚合物气凝胶具有超亲油性和疏水性等特点，无需进行任何处理，可直接用做油水分离材料。
在本发明一种优选的实施方式中，所述聚合物气凝胶通过将所述含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭情况下发生反应，再经预冷冻、冷冻干燥、热处理脱水脱氨后制备得到。
根据本发明，本发明中的聚合物气凝胶可以为各向异性气凝胶，也可以为各向同性气凝胶。
各向异性气凝胶与各向同性气凝胶区别是孔结构不同，各向异性气凝胶的气凝胶孔结构表现出长程有序，主要在于气凝胶在预冷冻阶段冰晶定向生长，生长过程中将杂质(本发明中的聚合物)排出，杂质聚集即形成孔壁；之后的冷冻干燥，即去除冰，得到有孔的气凝胶。因此，预冷冻时单向冷源温度不同可以得到各向异性气凝胶。单向冷源温度的实施方式可以有多种选择，包括但不限于预冷冻时，以液氮为低温冷源，将模具放在浸入液氮的铜柱上，冰晶从模具底部向上生长，最终形成各向异性孔结构的气凝胶。
各向异性气凝胶中气凝胶孔结构不同，轴向径向的导热系数不同，物质和声音传输速率也不同，可以根据不同的应用情况选取各向异性气凝胶/各向同 性气凝胶。例如，在本发明中相变材料在封装时，本发明的发明人发现，采用优选的各向异性气凝胶，泄漏量能够明显降低，而对各向异性气凝胶的方向没有要求。
本发明的第二个方面是提供一种聚合物气凝胶的制备方法，包括将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭条件下发生反应，再经预冷冻、冷冻干燥、热处理脱水脱氨，得到所述聚合物气凝胶。
本发明的气凝胶制备方法只需对水溶性气凝胶进行热处理，避免了引入交联剂或进行疏水处理制备疏水耐水气凝胶，制备方法简单易行，绿色环保，适用于各种类马来酰亚胺共聚物气凝胶的制备。本发明的气凝胶制备方法中不加入交联剂。
在本发明一种优选的实施方式中，所述制备方法包括以下具体步骤：
(1)将所述聚合物原料与氨水在密闭条件下发生反应，得到聚合物水溶液；
(2)将步骤(1)得到的聚合物水溶液先进行预冷冻，再经冷冻干燥，得到水溶性聚合物(即聚合物气凝胶前体)；
(3)将步骤(2)得到的水溶性聚合物进行热处理，得到所述聚合物气凝胶。
根据本发明，步骤(1)中聚合物原料、氨水的用量等可以在较宽的范围内选择，在本发明一种优选的实施方式中，步骤(1)中：
以反应体系的总质量为100％计，聚合物原料用量的质量分数为0.1％-30％，优选为0.5％-10％，更优选为1％-5％，以氨水中氨的质量计，氨用量的质量分数为0％-30％，优选为0.01％-10％，更优选为0.1％-1％，其余组分为水。
根据本发明，步骤(1)中的反应的条件等可以在较宽的范围内选择，在本发明一种优选的实施方式中，反应的条件包括：反应温度为0-200℃，优选为50-150℃，更优选为80-100℃，和/或，反应时间为0.01-100h，优选为0.5- 10h，更优选为1-5h。反应压力没有特殊限定，优选常压下进行。
在本发明一种优选的实施方式中，步骤(2)中包括将步骤(1)得到的聚合物水溶液于模具中预冷冻，得到冰块。模具可以为任意形状和任意大小，可根据所需气凝胶定制。冷冻可以采用冰箱等冷源，也可以使用液氮等进行冷冻。
所述预冷冻时水溶液的各个方向冷源温度相同或不同；此步骤若对应的预冷冻时混合液各个方向冷源温度一致，则所制备气凝胶为各向同性；若预冷冻时水溶液各个方向冷源温度不同，可制备各向异性气凝胶。优选预冷冻时单向冷源温度不同得到各向异性气凝胶。单向冷源温度的实施方式可以有多种选择，包括但不限于预冷冻时，以液氮为低温冷源，将模具放在浸入液氮的铜柱上，冰晶从模具底部向上生长，这样的实施方式。
具体地，预冷冻的条件可以是本领域的常规的温度条件，本发明没有特别的限制。
根据本发明，冷冻干燥的条件可以在较宽的范围内选择，本发明没有特别的限制，在本发明一种优选的实施方式中，冷冻干燥的条件包括：温度为-10℃以下，例如可以为-20℃以下，也可以为-30℃以下，根据本发明，冷冻干燥的真空度可以在较宽的范围内选择，在本发明一种优选的实施方式中，真空度为1000Pa以下，例如可以为100Pa以下，也可以为10Pa以下。以上冷冻干燥的条件可以根据成本、效率以及设备的常规作业方式进行灵活的选择。
冷冻干燥过程可以采用现有技术中的各种冷冻干燥设备，比如冷冻干燥机，冷冻喷雾干燥机，工业冷冻干燥机等。
根据本发明，步骤(3)中热处理的条件可以在较宽的范围内选择，在本发明一种优选的实施方式中，步骤(3)中热处理的条件包括：温度为100-300℃，优选为130-200℃，更优选为150-190℃，和/或，时间为0.1-10h，优选为0.5-3h，更优选为1-2h。
在本发明一种优选的实施方式中，所述聚合物原料能够与氨水反应得到水溶性聚合物。
根据本发明，所述聚合物原料可以在较宽的范围内选择，在本发明一种优选的实施方式中，所述聚合物原料为含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物；优选地，所述聚合物原料为包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共聚物；更优选地，所述烯烃单体包括α-甲基苯乙烯、苯乙烯、异丁烯中的至少一种。
作为举例，所述聚合物原料包括但不限于为苯乙烯马来酸酐共聚物、苯乙烯马来酸酐乙烯基硅油共聚物、马来酸酐异丁烯共聚物中的至少一种。优选地，所述聚合物原料包括苯乙烯马来酸酐共聚物、马来酸酐异丁烯共聚物中的至少一种。
更具体地，本发明所述聚合物气凝胶的制备过程包括以下步骤：a、将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭容器中发生反应，并加热，制备出聚合物水溶液；b、将聚合物水溶液倒入模具中，然后进行预冷冻，完全冻成冰块后，放入冷冻干燥机中冷冻干燥一定时间，以得到水溶性聚合物；c、对水溶性聚合物进行恒温条件下的热处理，以脱水脱氨得到耐水性马来酰亚胺基气凝胶。
以上所述的聚合物原料均现有技术已经公开的聚合物，可以来自现有技术市售，或根据现有技术所公开的方法来制备。
本发明中对密闭容器的材质没有特别限制，可以为金属、非金属、高分子等材料容器。
本发明涉及的“和/或”指的是“和/或”前后的两种条件可以择一，也可以两种条件并存。
本发明的第三个方面是提供一种聚合物气凝胶的回收方法，所述聚合物气凝胶为第一个方面所述的聚合物气凝胶或第二个方面所述的制备方法制备得到的聚合物气凝胶，回收方法包括将所述聚合物气凝胶和/或包含有所述聚 合物气凝胶的材料与氨水于密闭条件下混合反应，直至得到含有回收聚合物的水溶液，任选地除去不溶物，得到回收聚合物的水溶液。该气凝胶回收方法无需引入有机溶剂，不需要高温高压搅拌处理，只需一定浓度氨水优选保持100摄氏度以下，可实现快速高效回收，该方法能耗低，污染小，效率高，回收得到的聚合物溶液可再次用于聚合物气凝胶的制备。
本发明所述聚合物气凝胶的回收方法为：将聚合物气凝胶放置于一定浓度的氨水中，并置于密闭容器，在一定温度下加热，待其完全溶解，得到共聚物的水溶液。
根据本发明，回收方法中混合反应的条件可以在较宽的范围内选择，在本发明一种优选的实施方式中，混合反应的温度为0-200℃，优选为50-150℃，更优选为80-100℃，和/或，混合反应的时间为0.01-100h，优选为0.5-10h，更优选为1-5h。反应压力没有特殊限定，优选常压下进行。
在本发明一种优选的实施方式中，所述回收方法还包括将回收聚合物的水溶液经预冷冻、冷冻干燥、热处理，回收得到聚合物气凝胶。
根据本发明，所述预冷冻时水溶液的各个方向冷源温度相同或不同。预冷冻时水溶液各个方向冷源温度一致，则所制备气凝胶为各向同性；若预冷冻时水溶液各个方向冷源温度不同，则可制备得到各向异性气凝胶。优选预冷冻时单向冷源温度不同得到各向异性气凝胶。单向冷源温度的实施方式可以有多种选择，包括但不限于预冷冻时，以液氮为低温冷源，将模具放在浸入液氮的铜柱上，冰晶从模具底部向上生长，这样的实施方式。
根据本发明，冷冻干燥的条件可以在较宽的范围内选择，本发明没有特别的限制，在本发明一种优选的实施方式中，冷冻干燥的条件包括：温度为-10℃以下，例如可以为-20℃以下，也可以为-30℃以下，和/或，真空度为1000Pa以下，例如可以为100Pa以下，也可以为10Pa以下。
根据本发明，热处理的条件可以在较宽的范围内选择，在本发明一种优选的实施方式中，热处理的条件包括：
温度为100-300℃，优选为130-200℃，更优选为150-190℃和/或，时间为0.1-10h，优选为0.5-3h，更优选为1-2h。
本发明的第四个方面是提供一种根据第三个方面所述的回收方法得到的回收聚合物气凝胶。
采用以上方法所得到的聚合物气凝胶性能与初次制备的聚合物气凝胶性能相当，可以再次循环使用。
本发明的第五个方面是提供一种第一个方面所述的聚合物气凝胶、第二个方面所述的制备方法制备得到的聚合物气凝胶或者第四个方面所述的回收聚合物气凝胶在作为多孔材料优选作为载体、过滤材料和用于吸附有机相变材料，或者作为油水分离材料、保温材料中的应用。其中作为多孔材料使用时该聚合物气凝胶可以作为负载材料，如负载相变材料以避免其泄漏。
本发明所述的疏水聚合物气凝胶，无需表面处理即可用于油水分离，作为保温隔热气凝胶使用，亦可与其他组分共混制备多组分气凝胶，当其他组分不溶解于氨水时，也可以通过氨水实现多组分气凝胶的回收。
本发明的第六个方面是提供一种可回收蓄冷相变复合材料，包括聚合物气凝胶和负载于所述聚合物气凝胶中的相变材料；其中，所述聚合物气凝胶为第一个方面所述的聚合物气凝胶、第二个方面所述的制备方法制备得到的聚合物气凝胶或者第四个方面所述的回收聚合物气凝胶。
根据本发明，可回收蓄冷相变复合材料中相变材料、聚合物气凝胶的含量可以在较宽的范围内选择，在本发明一种优选的实施方式中，以所述可回收蓄冷相变复合材料的总质量为100％计，所述聚合物气凝胶的含量为2％-20％，优选为4％-10％例如可以为4％、5％、6％、7％、8％、9％、10％，以及任意两数值或者任意两数值的任意区间；所述相变材料的含量为80％-98％，优选为90％-96％。
优选地，所述聚合物气凝胶和所述相变材料的总质量之和为100％。
根据本发明，所述相变材料可以在较宽的范围内选择，只要具有蓄冷性能均可，所述相变材料包括但不限于为有机相变材料，优选所述有机相变材料的相变温度为(-10)-30℃，和/或，相变潜热为55-280J/g；更优选为烷烃类有机相变材料，进一步更优选为十烷、十二烷、十四烷中的至少一种。
在本发明一种优选的实施方式中，在所述相变材料为液态的温度条件下，所述可回收蓄冷相变复合材料中相变材料泄漏量小于10wt％，优选小于5wt％，更优选小于2wt％。
根据本发明，所述蓄冷相变复合材料中的聚合物气凝胶可以为各向异性气凝胶，也可以为各向同性气凝胶。
各向异性气凝胶与各向同性气凝胶区别是孔结构不同，各向异性气凝胶的气凝胶孔结构表现出长程有序，主要在于气凝胶在预冷冻阶段冰晶定向生长，生长过程中将杂质(本发明中的聚合物)排出，杂质聚集即形成孔壁；之后的冷冻干燥，即去除冰，得到有孔的气凝胶。因此，预冷冻时单向冷源温度不同可以得到各向异性气凝胶。单向冷源温度的实施方式可以有多种选择，包括但不限于预冷冻时，以液氮为低温冷源，将预冷冻容器放在浸入液氮的铜柱上，冰晶从预冷冻容器底部向上生长，最终形成各向异性孔结构的气凝胶。
各向异性气凝胶中气凝胶孔结构不同，轴向径向的导热系数不同，物质和声音传输速率也不同，可以根据不同的应用情况选取各向异性气凝胶/各向同性气凝胶。例如，在本发明中相变材料在封装时，本发明的发明人发现，采用优选的各向异性气凝胶，泄漏量能够明显降低，而对各向异性气凝胶的方向没有要求。
在本发明一种优选的实施方式中，所述蓄冷相变复合材料中的聚合物气凝胶为各向异性气凝胶，优选为预冷冻时单向冷源温度不同所得的各向异性气凝胶。在此优选的实施方式中，所述相变材料为液态的温度条件下，所述可回收蓄冷相变复合材料中相变材料泄漏量更低。
在本发明一种优选的实施方式中，所述聚合物气凝胶能够溶于0-150℃的 氨水中，形成含有聚合物的溶液，优选地，含有聚合物的溶液经预冷冻、冷冻干燥、热处理，能够回收得到聚合物气凝胶。
在本发明一种优选的实施方式中，所述聚合物气凝胶的导热系数为0.05W/(m·k)以下，优选为0.04W/(m·k)以下。本发明所述的聚合物气凝胶具有低热导率的特点，无需进行任何处理，可直接作为保温材料使用。
在本发明一种优选的实施方式中，所述聚合物气凝胶的密度为100kg/m3以下，优选为10-100kg/m3，优选为15-80kg/m3具体地，例如，15kg/m3、35kg/m3、45kg/m3、55kg/m3、65kg/m3、75kg/m3、80kg/m3，以及任意两数值或者任意两数值的任意区间；和/或，所述聚合物气凝胶为多孔材料。本发明所述的聚合物气凝胶孔隙率高，是一种多孔材料，可以作为载体使用。例如作为骨架负载有机相变材料，避免相变材料的泄漏，所制备的相变复合材料亦可通过氨水进行回收。
在本发明一种优选的实施方式中，以含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元的总摩尔量为100％计，所述聚合物中含马来酰亚胺基团的结构单元的摩尔比例为5％-70％，优选为10％-60％；更优选为20％-50％，例如20％、25％、30％、35％、40％、45％、50％，以及任意两数值或者任意两数值的任意区间。
根据本发明，所述聚合物可以在较宽的范围内选择，在本发明一种优选的实施方式中，所述聚合物衍生自含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料。
马来酸酐基团指的是马来酰亚胺基团指的是马来酸及铵盐基团、马来酰胺酸及铵盐基团指的是 式中M相同或不同，各自为羟基或氨基或铵(-ONH4)。
根据本发明，所述聚合物是碳链聚合物，其中杂原子O和N存在于侧基中。
优选地，所述聚合物原料为包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共聚物；更优选地，所述烯烃单体为α-甲基苯乙烯、苯乙烯、异丁烯中的至少一种。
在本发明一种优选的实施方式中，所述聚合物气凝胶能够溶于0-150℃的氨水中，形成含有聚合物的溶液；优选地，含有聚合物的溶液经预冷冻、冷冻干燥、热处理，能够回收得到聚合物气凝胶。基于此，本发明的聚合物气凝胶能够方便环保地实现回收利用。
在本发明一种优选的实施方式中，所述聚合物气凝胶具有光致发光性能且能够随着温度的变化光信号发生变化。还可以利用本发明中的所述聚合物气凝胶的光致发光性能作为显示温度变化的指示材料。
在本发明一种优选的实施方式中，所述聚合物气凝胶的静态水接触角在100°以上，优选110°以上，更优选在135°以上。在本发明一种优选的实施方式中，所述聚合物气凝胶不溶于水，优选将所述聚合物气凝胶置于20-40℃水中浸泡24h，优选浸泡72h，更优选浸泡168h后，不会溶解形成聚合物的水溶液。本发明所述的聚合物气凝胶具有超亲油性和疏水性等特点，无需进行任何处理，可直接用做油水分离材料。
在本发明一种优选的实施方式中，所述聚合物气凝胶的制备方法，包括将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭条件下发生反应，再经预冷冻、冷冻干燥、热处理脱水脱氨，得到所述聚合物气凝胶。
本发明的气凝胶制备方法只需对水溶性气凝胶进行热处理，避免了引入 交联剂或进行疏水处理制备疏水耐水气凝胶，制备方法简单易行，绿色环保，适用于各种类马来酰亚胺共聚物气凝胶的制备。本发明的气凝胶制备方法中不加入交联剂。
本发明的第七个方面是提供一种第六个方面所述的可回收蓄冷相变复合材料的制备方法，包括将所述相变材料负载在所述聚合物气凝胶中；优选地，先制备聚合物气凝胶，再将所述相变材料负载在所述聚合物气凝胶中。
其中所述的将相变材料负载在所述聚合物气凝胶中的方法，可以是现有技术中已有的各种负载方式。具体可以是将相变材料处于液态状况下通过填充、注入的方式使得相变材料吸附和/或渗透于所述的复合气凝胶中而实现相变材料的负载。
其中聚合物气凝胶的制备方法，包括将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭条件下发生反应，再经预冷冻、冷冻干燥、热处理脱水脱氨，得到所述聚合物气凝胶。
本发明的气凝胶制备方法只需对水溶性气凝胶进行热处理，避免了引入交联剂或进行疏水处理制备疏水耐水气凝胶，制备方法简单易行，绿色环保，适用于各种类马来酰亚胺共聚物气凝胶的制备。
在本发明一种优选的实施方式中，所述制备方法包括以下步骤：(1)将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭条件下发生反应，得到聚合物水溶液；(2)将步骤(1)得到的聚合物水溶液先进行预冷冻，再经冷冻干燥，得到水溶性聚合物(即聚合物气凝胶前体)；(3)将步骤(2)得到的水溶性聚合物进行热处理，得到所述聚合物气凝胶；(4)将所述相变材料负载在所述聚合物气凝胶中。
根据本发明，步骤(1)中聚合物原料、氨水的用量等可以在较宽的范围内选择，在本发明一种优选的实施方式中，步骤(1)中：
以反应体系的总质量为100％计，聚合物原料用量的质量分数为0.1％-30％，优选为1％-10％，更优选为2％-5％，以氨水中氨的质量计，原料中氨用量的质量分数为0.001％-30％，优选为0.01％-10％，更优选为0.1％-1％，其余组分为水。
根据本发明，步骤(1)中的反应的条件等可以在较宽的范围内选择，在本发明一种优选的实施方式中，反应的条件包括：反应温度为0-200℃，优选为50-150℃，更优选为80-100℃，和/或，反应时间为0.01-100h，优选为0.5-10h，更优选为1-5h。
在本发明一种优选的实施方式中，步骤(2)中包括将步骤(1)得到的聚合物水溶液于预冷冻容器中预冷冻，得到冰块。预冷冻容器可以为任意形状和任意大小，可根据所需气凝胶定制。冷冻可以采用冰箱等冷源，也可以使用液氮等进行冷冻。此步骤若预冷冻容器的各个方向冷源温度一致，则所制备气凝胶为各向同性；若预冷冻容器的各个方向冷源温度不同，可制备各向异性气凝胶。优选预冷冻时单向冷源温度不同可以得到各向异性气凝胶。单向冷源温度的实施方式可以有多种选择，包括但不限于预冷冻时，以液氮为低温冷源，将预冷冻容器放在浸入液氮的铜柱上，冰晶从容器底部向上生长，这样的实施方式。
具体地，预冷冻的条件可以是本领域的常规的温度条件，本发明没有特别的限制，使得聚合物水溶液冷冻成冰即可。
根据本发明，冷冻干燥的条件可以在较宽的范围内选择，本发明没有特别的限制，在本发明一种优选的实施方式中，冷冻干燥的条件包括：温度为-10℃以下，例如可以为-20℃以下，也可以为-30℃以下，根据本发明，冷冻干燥的真空度可以在较宽的范围内选择，在本发明一种优选的实施方式中，真空度为1000Pa以下，例如可以为100Pa以下，也可以为10Pa以下。以上冷冻干燥的条件可以根据成本、效率以及设备的常规作业方式进行灵活的选择。
冷冻干燥过程可以采用现有技术中的各种冷冻干燥设备，比如冷冻干燥 机，冷冻喷雾干燥机，工业冷冻干燥机等。
根据本发明，步骤(3)中热处理的条件可以在较宽的范围内选择，在本发明一种优选的实施方式中，步骤(3)中热处理的条件包括：
温度为100-300℃，优选为130-200℃，更优选为150-190℃，和/或，时间为0.1-10h，优选为0.5-3h，更优选为1-2h。反应压力没有特殊限定，优选常压下进行。
根据本发明，所述聚合物原料可以在较宽的范围内选择，在本发明一种优选的实施方式中，所述聚合物原料为含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物；优选地，所述聚合物原料为包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共聚物；更优选地，所述烯烃单体包括α-甲基苯乙烯、苯乙烯、异丁烯、醋酸乙烯酯中的至少一种。
作为举例，所述聚合物原料包括但不限于苯乙烯马来酸酐共聚物、甲基苯乙烯马来酸酐共聚物、马来酸酐异丁烯共聚物中的至少一种。
以上所述的聚合物原料均现有技术已经公开的聚合物，可以来自现有技术市售，或根据现有技术所公开的方法来制备。
本发明中对密闭容器的材质没有特别限制，可以为金属、非金属、高分子等材料容器。
更具体地，本发明所述聚合物气凝胶的制备过程包括以下步骤：a、将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭容器中发生反应，并加热，制备出聚合物水溶液；b、将聚合物水溶液倒入预冷冻容器中，然后进行预冷冻，完全冻成冰块后，放入冷冻干燥机中冷冻干燥一定时间，以得到水溶性聚合物；c、对水溶性聚合物进行恒温条件下的热处理，以脱水脱氨得到耐水性马来酰亚胺基气凝胶。
预冷冻时溶液的各个方向冷源温度相同或不同，更优选地，预冷冻时溶液 的各个方向冷源温度不同，得到各向异性气凝胶；最优选地，所述预冷冻溶液单向冷源温度不同，得到各向异性气凝胶。
在本发明一种优选的实施方式中，在预冷冻阶段，步骤(1)得到的聚合物水溶液的各个方向冷源温度不同，优选单向冷源温度不同。
在本发明一种更优选的实施方式中，在步骤(2)进行预冷冻前，将模具插入所述步骤(1)得到的聚合物水溶液中，所述模具可以插到底接触到预冷冻容器底部，也可以和预冷冻容器底部留有距离，优选后者；并在步骤(3)的热处理后，任选地取出模具，得到具有空腔的聚合物气凝胶，步骤(4)中将相变材料填充至所述聚合物气凝胶中。这样，可以在将预储存物放在取出模具后留下的空腔中，以利于储存。
本发明中的模具在带有空腔结构的情况下也可以不取出，在使用时可以将预储存物放置在模具的空腔中。同时，冷藏物(如疫苗、药品等)放置在空腔中，使得冷藏物所处的蓄冷环境更均匀，保藏效果更好。
对于所述模具的选择，本发明没有特别的限制，材质可以为玻璃，也可以为塑料、金属等；所述模具可以是实心的，也可以是带有空腔结构的，其形状不受限制，优选筒状、柱状等；对于模具的结构，在取出的情况下，可以是实心的，也可以具有空腔结构；在不取出的情况下，所述模具优选具有上部能够开口的空腔结构；对于模具的大小，可以根据预储存物的大小调节，本发明没有特别的限制。
本发明涉及的“和/或”指的是“和/或”前后的两种条件可以择一，也可以两种条件并存。
对相变材料温度的实时监测也是十分重要的，例如包括新冠疫苗在内的大多数疫苗在运输和储存过程中必须保持在8℃以下，因此，需要对每一支疫苗进行实时的温度监测。有机相变材料还需要考虑可再加工性和可回收性，避免其造成环境污染和资源浪费。
基于上述技术问题，本发明的第八个方面是提供一种具有实时温度监测 功能的可回收蓄冷相变材料，所述可回收蓄冷相变材料具有层结构，包括由第六个方面所述的可回收蓄冷相变复合材料或者第七个方面所述的制备方法制备得到的可回收蓄冷相变复合材料形成的内层，和第二聚合物气凝胶形成的外层。
根据本发明，内层的厚度和所述外层的厚度可以在较宽的范围内选择，在本发明一种优选的实施方式中，所述内层的厚度为3mm以上，所述外层的厚度为5mm以上。
在本发明一种优选的实施方式中，所述内层与所述外层之间还具有间隔层。对于间隔层的选材，本发明没有特别的限制，只要能够将相变材料在内部封装的气凝胶与外部的保温的气凝胶之间隔开，避免相互渗透即可。包括但不限于金属(例如薄铝箔)、塑料等。
以上内层的厚度可以在制备过程中根据模具四壁或者四壁和底部距离间隔层的距离进行控制。而外层的厚度，可以根据间隔层的四周距外面容器器壁的距离进行控制。
以上可回收蓄冷相变材料可以是径向层结构的圆柱状，外层为第二聚合物气凝胶，内层为可回收蓄冷相变复合材料，两层之间设置间隔层；或者以上可回收蓄冷相变材料可以是层结构的平板状，其中间为间隔层，间隔层一侧为第二聚合物气凝胶的外层，另一侧为可回收蓄冷相变复合材料的内层；优选地，所述可回收蓄冷相变材料最外面还包裹有封装材料。对于间隔层的形状结构本发明也没有特别的限制，比如可以是筒状，也可以是平板，只要能够包覆在内层气凝胶外面隔绝开内外层即可。
优选地，所述内层设置有空腔；所述空腔来自于模具本身或取出模具后形成的空腔。应用中将冷藏物(如疫苗、药品等)也可放置在空腔中，使得冷藏物所处的蓄冷环境更均匀，保藏效果更好。
根据本发明，所述第二聚合物气凝胶可以在较宽的范围内选择，优选地，所述第二聚合物气凝胶具有光致发光性能(即荧光性能)且能够随着温度的变 化光信号发生变化。此处的光信号指的是荧光光谱峰位置和/或强度。
在本发明一种优选的实施方式中，所述第二聚合物气凝胶选自根据第六方面所述的可回收蓄冷相变复合材料中的具有光致发光性能(即荧光性能)且能够随着温度的变化光信号发生变化的聚合物气凝胶的至少一种；且第二聚合物气凝胶与所述的可回收蓄冷相变复合材料中的聚合物气凝胶可以相同或不同。更优选地，所述第二聚合物为苯乙烯马来酸酐马来酰亚胺共聚物气凝胶(即为包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与苯乙烯形成的共聚物)，本发明的发明人发现，苯乙烯马来酸酐马来酰亚胺共聚物气凝胶具有能够随着温度的变化光信号发生变化的荧光性能。
作为举例，在本发明一种具体的实施方式中，本发明所述的相变蓄冷材料的特点为内层为第六方面所述的气凝胶相变复合材料，外层为作为第六方面所述的气凝胶相变复合材料中所用的聚合物气凝胶，优选该气凝胶具有光致发光效果(例如可以为苯乙烯马来酸酐/马来酰亚胺共聚物气凝胶)，且强度随温度变化而变化(例如随温度的降低而升高)，因此，可以通过对荧光强度的测定，确定相变材料的温度，实现对蓄冷材料实时的温度监控。
本发明的第九个方面是提供一种第八个方面所述的具有实时温度监测功能的可回收蓄冷相变材料的制备方法，其特征在于包括以下步骤：
(1)将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭情况下发生反应，得到聚合物水溶液；
(2)将聚合物水溶液置于间隔层内侧空间或间隔层内侧与模具之间的空间，然后进行预冷冻，再经冷冻干燥，得到水溶性聚合物(即聚合物气凝胶前体)；
(3)将步骤(2)得到的水溶性聚合物进行热处理，任选地取出模具，得到具有空腔的聚合物气凝胶；
(4)将相变材料填充在步骤(3)得到的聚合物气凝胶中，形成所述可回收蓄冷相变材料的内层；
其中，在步骤(2)、步骤(3)、步骤(4)中和/或步骤之间和/或步骤(4)之后将第二聚合物气凝胶包覆在间隔层外侧，从而形成所述可回收蓄冷相变材料的外层；
或者，
在步骤(2)中将含有第二聚合物气凝胶的水溶液和/或第二聚合物水溶液置于间隔层外侧空间，从而形成所述可回收蓄冷相变材料的外层；优选地，第二聚合物水溶液与步骤(1)的聚合物水溶液相同；
也就是说，步骤(2)优选按照以下方式进行：
将所述聚合物水溶液分别置于间隔层外侧空间，间隔层内侧空间或间隔层内侧与模具之间的空间，得到具有层结构的水溶性聚合物。
根据上述技术方案，本发明的具有实时温度监测功能的可回收蓄冷相变材料的制备方法包括聚合物气凝胶的制备过程，可以采用前文所述的聚合物气凝胶(可回收聚合物气凝胶)的制备方法得到位于间隔层内的聚合物气凝胶，同时，在内层聚合物气凝胶的制备过程中，将第二聚合物气凝胶或含有第二聚合物气凝胶的水溶液和/或第二聚合物水溶液包覆在间隔层外。至于何时将第二聚合物气凝胶或含有第二聚合物气凝胶的水溶液和/或第二聚合物水溶液包覆在间隔层外，可以根据选用的第二聚合物气凝胶的种类进行选择。例如，当第二聚合物气凝胶为前文所述的聚合物气凝胶(即与内层的聚合物气凝胶种类相同)时，可以选择在步骤(2)将步骤(1)中的水溶性聚合物设置在间隔层外，之后进行后续的处理步骤，这样，在步骤(3)的处理步骤后，间隔层内外均为可回收的聚合物气凝胶；如果第二聚合物气凝胶(或前体)不需要冻干但需要热处理，也可以将第二聚合物气凝胶(或前体)在步骤(2)设置在间隔层外；第二聚合物气凝胶(或前体)不需要热处理时，也可以将第二聚合物气凝胶成品在步骤(3)或步骤(4)或步骤(4)之后设置在间隔层外，总 之，以程序或工艺节约为原则，根据第二聚合物气凝胶的种类可以灵活调整。
具体地，内层和外层中气凝胶原料的用量，可以在较宽的范围内选择，优选其用量使得成品中所述内层的厚度为3mm以上，所述外层的厚度为5mm以上。
对于所述第二聚合物气凝胶或(前体)的选材、相变材料的选材、用量等，可以采用第八方面所述的第二聚合物气凝胶或(前体)的选材、相变材料的选材、用量，在此不再赘述。
在本发明一种优选的实施方式中，内层的聚合物水溶液中聚合物含量的质量分数为0.1％-30％，优选1％-10％，更优选为2％-5％，和/或，第二聚合物气凝胶的水溶液和/或第二聚合物水溶液中第二聚合物含量的质量分数各自为0.1％-30％，优选0.5％-10％，更优选1％-5％。
在本发明一种优选的实施方式中，步骤(2)中，在预冷冻阶段，步骤(1)得到的聚合物水溶液的各个方向冷源温度不同，优选单向冷源温度不同。这样，可以得到各向异性的气凝胶，在此优选的实施方式中，所得的蓄冷材料的泄漏量更低。
预冷冻容器可以为任意形状和任意大小，可根据所需气凝胶或冷藏物的形状定制。冷冻可以采用冰箱等冷源，也可以使用液氮等进行冷冻。此步骤若模具各个方向冷源温度一致，则所制备气凝胶为各向同性；若预冷冻容器各个方向冷源温度不同，可制备各向异性气凝胶，本发明优选各向异性气凝胶，更优选单向冷源温度不同的各向异性气凝胶。
以上步骤(1)、步骤(2)、步骤(3)中的具体的条件均可以在较宽的范围内选择，优选可以采用上述制备聚合物气凝胶的制备方法中的优选的条件。
更具体的，步骤(3)中热处理温度为100-300℃，优选为120-220℃，更优选为160-200℃；热处理时间为0.1-10小时，优选为0.5-3小时，更优选为1-2小时。
根据本发明，以上涉及的可回收蓄冷相变复合材料中可回收聚合物气凝 胶的回收方法可以采用以下方法：
回收方法包括将所述聚合物气凝胶和/或包含有所述聚合物气凝胶的材料与氨水于密闭条件下混合反应，直至得到含有回收聚合物的水溶液，任选地除去不溶物，得到回收聚合物的水溶液。该气凝胶回收方法无需引入有机溶剂，不需要高温高压搅拌处理，只需一定浓度氨水优选保持100摄氏度以下，可实现快速高效回收，该方法能耗低，污染小，效率高，回收得到的聚合物溶液可再次用于聚合物气凝胶的制备。
本发明所述聚合物气凝胶的回收方法为：将聚合物气凝胶放置于一定浓度的氨水中，并置于密闭容器，在一定温度下加热，待其完全溶解，得到共聚物的水溶液。
根据本发明，回收方法中混合反应的条件可以在较宽的范围内选择，在本发明一种优选的实施方式中，混合反应的温度为0-200℃，优选为50-150℃，更优选为80-100℃，和/或，混合反应的时间为0.01-100h，优选为0.5-10h，更优选为1-5h。
在本发明一种优选的实施方式中，所述回收方法还包括将回收聚合物的水溶液经冷冻干燥、热处理，回收得到聚合物气凝胶；优选地，冷冻干燥的条件包括：温度为-10℃以下，可以为-20℃以下，也可以为-30℃以下，和/或，真空度为1000Pa以下，可以为100Pa以下，也可以为10Pa以下。
根据本发明，热处理的条件可以在较宽的范围内选择，在本发明一种优选的实施方式中，热处理的条件包括：
温度为100-300℃，优选为130-200℃，更优选为150-190℃和/或，时间为0.1-10h，优选为0.5-3h，更优选为1-2h。
涉及到本发明中的可回收蓄冷相变复合材料以及具有实时温度监测功能的可回收蓄冷相变材料中的可回收聚合物气凝胶的回收时，则可以采用上述的方法，将可回收蓄冷相变复合材料或将具有实时温度监测功能的可回收蓄冷相变材料中内层的可回收蓄冷相变复合材料于氨水中进行处理，将聚合物 与相变材料分离，再经过后处理的步骤，得到可回收聚合物气凝胶，或者再沿用可回收蓄冷相变复合材料或具有实时温度监测功能的可回收蓄冷相变材料的制备方法，得到本发明中的可回收蓄冷相变复合材料或具有实时温度监测功能的可回收蓄冷相变材料。
当第二聚合物气凝胶为本发明中的可回收聚合物气凝胶时(所述聚合物气凝胶中的聚合物中含有马来酸酐基团和马来酰亚胺基团)，可以沿用上述方法，与内层的材料一起回收，当第二聚合物气凝胶为不同种的聚合物气凝胶时，可以将具有实时温度监测功能的可回收蓄冷相变材料外层的第二聚合物气凝胶剥除，再进行后续的回收步骤。
本发明的第十个方面是提供一种第六个方面所述的可回收蓄冷相变复合材料或者第七个方面所述的制备方法制备得到的可回收蓄冷相变复合材料、第八个方面所述的具有实时温度监测功能的可回收蓄冷相变材料或者第九个方面所述的制备方法制备得到的具有实时温度监测功能的可回收蓄冷相变材料在食品保鲜、冷链运输领域中的应用。
根据上述技术方案，本发明提供了一种可回收聚合物气凝胶及其制备方法、回收方法和应用。本发明还提供了一种可回收蓄冷相变复合材料、具有实时温度监测功能的可回收气凝胶相变蓄冷材料及其制备方法和应用。与现有技术相比，本发明具有以下优势：
本发明的聚合物气凝胶不需要经过交联或疏水化处理，即具有超亲油性和疏水性等特点，无需进行任何处理，可直接用做油水分离材料；本发明的聚合物气凝胶还能够方便环保地实现回收利用，回收效率可高于99％，气凝胶制备回收过程无需使用任何有机溶剂，具有低能高效、绿色环保的特点。不仅如此，本发明的聚合物气凝胶导热系数低、密度小、耐热性较好，能够用于多种领域，具有极高的应用价值。本发明首次将马来酰亚胺基的聚合物制备成气 凝胶，拓宽了含有马来酸酐基、马来酰亚胺基共聚物的应用范围。
本发明中的可回收蓄冷相变复合材料，包括聚合物气凝胶和负载于所述聚合物气凝胶中的相变材料；其中，所述聚合物气凝胶中的聚合物中含有含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元。该聚合物气凝胶可于氨水中回收，同时经过后处理(包括热处理)得到回收的聚合物气凝胶，能够再次得到重复利用，基于此，本发明中的可回收蓄冷相变复合材料可反复回收利用。本发明中的可回收蓄冷相变复合材料不仅可回收，而且储冷性能强，且相变材料的泄漏量更少，能够保持长时间的低温，可广泛应用于在食品保鲜、冷链运输领域(例如疫苗、药品的冷链运输)等环节。
不仅如此，本发明中的具有实时温度监测功能的可回收蓄冷相变材料，具有夹层结构，包括由可回收蓄冷相变复合材料形成的内层，和第二聚合物气凝胶形成的外层，可以实现性能更优的保温，在优选的第二聚合物气凝胶具有光致发光性能且能够随着温度的变化光信号发生变化的情况下，可以更好地实现温度监控，这样可以同时实现大批量温度监控和可回收性能。
附图说明
图1是对比例3A、实施例1A及实施例1A回收所得气凝胶傅里叶变换红外光谱测试曲线；
图2是实施例1A及实施例1A回收所得气凝胶核磁共振氢谱曲线；
由图1、图2可见，在傅里叶红外光谱(图1)中，3207cm-1和3444cm-1处存在明显的N-H伸缩振动吸收峰和氢键特征吸收峰，表明酰胺基团的存在；1780cm-1和1857cm-1处为马来酸酐中C＝O的不对称伸缩振动和对称伸缩振动峰，1716cm-1和1662cm-1的吸收峰表明羧基和酰胺基团的存在。在935cm-1处是酸酐五元环中C-O-C的特征吸收峰，而1349cm-1处的吸收峰属于酰亚胺环独有的C-N伸缩振动峰。在核磁共振氢谱(图2)中，苯环上5个氢的化学位移在7.7～6.0ppm之间，马来酰亚胺的N-H上的氢的化学位移在10.2～9.4ppm 之间。以苯环上的氢为内标，通过马来酰亚胺与苯环上的氢积分面积，可以计算出马来酰亚胺与马来酸酐(聚合物原料中的马来酸酐，等于聚合物气凝胶中马来酸酐+马来酰亚胺的总量)的比值(即马来酰亚胺化率)。综上，从图1的气凝胶红外光谱测试曲线和图2的气凝胶核磁共振氢谱曲线可以确定气凝胶结构中，有马来酰亚胺结构的存在。
图3是实施例1A所得气凝胶孔结构的扫描电子显微镜照片，可以证明气凝胶的多孔结构的存在。
图4实施例1B所得蓄冷相变材料升温曲线；
图4测试结果表明，所制备相变材料能够保持长时间的低温；
图5实施例1B所制备的相变蓄冷材料外层的马来酰亚胺基气凝胶在400nm激发波长下的发射光谱。
图5表明通过表面气凝胶的荧光-温度关系，可以对相变材料的温度实时监测。
图6为回收实施例B中的可回收蓄冷相变复合材料(a)及回收的相变材料(b)和回收的聚合物气凝胶(c)的外观示意图。可见，本发明中的可回收蓄冷相变复合材料可以回收利用；
图7为实施例1B所得的具有实时温度监测功能的气凝胶相变蓄冷材料的立体结构示意图；
图8为实施例1B所得的具有实时温度监测功能的气凝胶相变蓄冷材料的纵剖面结构示意图。
其中，1—外层；2—间隔层；3—内层；4—空腔。
具体实施方式
下面结合具体实施例对本发明进行具体的描述，有必要在此指出的是以下实施例只用于对本发明的进一步说明，不能理解为对本发明保护范围的限制，本领域技术人员根据本发明内容对本发明做出的一些非本质的改进和调 整仍属本发明的保护范围。
实施例中的实验数据使用以下仪器及测定方法测定：
1、气凝胶的水溶性测量方法：
取1g气凝胶放入100g水中，室温下浸泡72小时后，取出烘干，称得质量m1。当m1＞99％时，认为该聚合物气凝胶为耐水性。当气凝胶放入水中完全溶解，认为该气凝胶为水溶性气凝胶。
2、气凝胶的水接触角测量方法：
实施例所得产品的水接触角，采用德国EASYDROP接触角测试仪进行测定：用薄刀片将聚合物气凝胶切割为约10*10*2mm3的薄片，将气凝胶片固定于操作台上，固定过程中保持试样在水平方向上平整，然后将载玻片放置在EASYDROP接触角测量仪的样品台上固定，调节仪器控制体积为4±0.02μL水滴滴到样品中央，将水滴滴于气凝胶表面l min后，开始测量三相交界处自固液界面经液滴内部至汽液界面的夹角，即为水静态接触角(简称水接触角)。
3、气凝胶的导热系数测量方法：
使用西安夏溪电子科技有限公司公司生产TC3100型号的热线法通用型导热系数仪。首先将气凝胶用薄刀片切割为约30*20*5mm3的薄片，用两片气凝胶薄片覆盖在测试的探头两侧，使用砝码压紧后，调节测试温度为25摄氏度，设置测试方法为保温材料样品测试，测试结果所得导热系数为至少5次测量结果的平均值。
4、气凝胶的结构傅里叶变换红外光谱表征方法：
使用美国Nicolet的IS5傅里叶变换红外光谱仪对实施例中气凝胶进行测试。通过KBr压片的方法采集样品的红外光谱图，取适量气凝胶，与KBr共同研磨，压片后测试，扫描次数设置为32，光谱采集的范围为400-4000cm，光学频率为1cm-1。
5、气凝胶的结构核磁共振氢谱表征方法：
使用美国Agilent公司400-MR DD2核磁共振波谱仪对实施例中的气凝 胶样品进行1H NMR测试。其中，水溶性气凝胶采用二甲基亚砜-d6作为溶剂，疏水耐水气凝胶使用丙酮-d6作为溶剂，四甲基硅烷(TMS)作为内参比试剂。
6、气凝胶孔结构测试方法：
使用韩国COXEM公司的EM30AX扫描电子显微镜对实施例中的气凝胶样品进行孔结构观察。首先将待测试的样品用金在表面进行涂层，而后将涂层完后的样品放入扫描电子显微镜检测台上，用扫描电子显微镜扫描试样上的区域得到孔结构照片。
7、气凝胶的热稳定性测试方法：
采用热重分析(TGA,Mettler Toledo,Switzerland)测定样品的热稳定性，取5mg气凝胶进行测试。测试在氮气流下进行，升温速率为20℃/min，温度范围从50℃到550℃。
8、玻璃化转变温度测试方法：
样品的玻璃化转变温度使用Perkin-Elmer pyris-1差示扫描量热仪(DSC)进行，使用铟和锌标准校准。5-6mg样品来自注射棒，在氮气流下从150℃加热到300℃，在300℃保持3分钟。接下来，样品冷却到150℃1分钟，再次加热到300℃。所有加热和冷却过程的编程速度为10℃/min。根据DSC曲线中的相关峰测定玻璃化转变温度(Tg)。
9、泄漏量测试方法：
取15g实施例所得样品，取滤纸放于30℃热台上，将样品倒置放于滤纸上10分钟，取下样品，对样品称重得m(g)，泄漏量为：m/15*100wt％。若样品完全融化，无法取下，泄漏量为100wt％。
10、三维荧光光谱测试方法：
上述纳米荧光弹性粒子的荧光光谱的测试仪器为：F-7000 FLSpectrophotometer，测试方式为Wavelength scan，激发波长设定为400nm，测定发射光谱。
11、相变材料蓄冷能力测试方法：
向10mL玻璃小瓶中加入10mL乙醇并冷冻至-30℃后，置于25摄氏度恒温箱中，将热电偶插入至乙醇中，评估蓄冷效果。
12、相变材料吸附量测试方法：
使用天平对测试前的整个样品称重为m1，待吸附相变材料并倒置擦干表面过量的相变材料后，对整个样品称重为m2，相变材料吸附量为：m2-m1。
13、相变温度测试方法：
采用差示扫描量热法(DSC)测量气凝胶和相变材料的热性能，采用铟和锌标准品校准的Perkin-Elmer pyris-1。对于气凝胶，样品在氮气流下从20-150℃加热，在20℃和150℃分别保持5min。对于相变材料，样品在氮气流下从50℃加热到300℃，分别在50℃和300℃保存5min。所有加热和冷却过程的编程速度为20℃/min。根据DSC曲线的相关峰确定熔融潜热ΔHm和凝固潜热ΔHf以及熔融温度Tm和凝固温度Tf。
实施例中所用的原料描述于表I中。
表I

制备例1A
将500ml乙酸异戊酯置于1000ml三口烧瓶，通入氮气30min除去氧气，将24.5g马来酸酐和26g苯乙烯加入烧瓶中。待完全溶解后，加入0.4g偶氮二异丁腈，将水浴锅温度升温至70℃，反应7h。反应后在10000r下离心10min，除去上清液，加入500ml甲醇，搅拌0.5小时，离心后去除去上清液，重复两次，然后140℃真空干燥24h，得到苯乙烯马来酸酐共聚物。
制备例2A
将500ml乙酸异戊酯置于1000ml三口烧瓶，通入氮气30min除去氧气，将24.5g马来酸酐和26.2g苯乙烯加入烧瓶中，滴入3.69g大易DY-V421乙烯基硅油。待完全溶解后，加入0.4g偶氮二异丁腈，将水浴锅温度升温至70℃，反应7h。反应后在10000r下离心10min，除去上清液，加入500ml甲醇，搅拌0.5小时，离心后去除去上清液，重复两次，然后140℃真空干燥24h，得到苯乙烯马来酸酐乙烯基硅油共聚物。
制备例3A
取制备例1A中苯乙烯马来酸酐共聚物，在带盖玻璃瓶中加入91.5g水，再加入3.5g质量分数为25％氨水和5g上述马来酸酐-苯乙烯共聚物，将玻璃瓶盖旋紧后放入烘箱中保持95℃，4小时后取出得到均一的5％质量分数聚合物溶液，室温下晾干得含有马来酰胺酸、马来酸铵基团的聚合物。
实施例1A
取带盖玻璃瓶，加入91.5g水，再加入3.5g质量分数为25％氨水和5g马 来酸酐-苯乙烯共聚物，将玻璃瓶盖旋紧后放入烘箱中保持95℃，4小时后取出得到均一的5％质量分数聚合物溶液。
将聚合物溶液倒入6个模具中，每个模具倒入15ml溶液，并置于-30℃冰箱冷冻2小时，将冷冻好的样品转移到冷冻干燥机中冷冻干燥(-30℃以下，10Pa以下)72小时后，取出得到的水溶性聚合物；
将水溶性聚合物置入恒温容器中180℃进行热处理2h，以脱水脱氨得到马来酰亚胺基气凝胶(即本发明中的聚合物气凝胶)。
对比例1A
将实施例1A中91.5g水和3.5g质量分数为25％氨水替换为94g水和1g氢氧化钠，其他制备步骤与实施例1A相同。
对比例2A
将实施例1A中91.5g水和3.5g质量分数为25％氨水替换为94g水和2g氢氧化钠，其他制备步骤与实施例1A相同。
对比例3A
不进行实施例1A过程中的热处理过程，其他制备步骤与实施例1A相同。
对比例4A
将实施例1A中马来酸酐-苯乙烯共聚物中的马来酸酐替换为氮苯基马来酰亚胺，其他制备步骤与实施例1A相同。
实施例2A
将实施例1A中91.5g水、3.5g质量分数为25％氨水和5g马来酸酐-苯乙烯共聚物，变为94.9g水、2.1g 25％氨水和3g马来酸酐苯乙烯共聚物，其他制备步骤与实施例1A相同。
实施例3A
将实施例1A中91.5g水、3.5g质量分数为25％氨水和5g马来酸酐-苯乙烯共聚物，变为98.3g水、0.7g 25％氨水和1g马来酸酐苯乙烯共聚物，其他制备步骤与实施例1A相同。
实施例4A
将实施例1A中5g马来酸酐-苯乙烯共聚物，变为5g马来酸酐异丁烯共聚物(可乐丽ISOBAM-08)，其他制备步骤与实施例1A相同。
实施例5A
将实施例1A中5g马来酸酐-苯乙烯共聚物，变为5g制备例3A中所得的聚合物，其他制备步骤与实施例1A相同。
实施例6A
将实施例1A中马来酸酐共聚物替换为制备例2A中的苯乙烯马来酸酐乙烯基硅油共聚物，其他制备步骤与实施例1A相同。
实施例7A
按照实施例5A的方法，将加入3.5g质量分数为25％氨水替换为加入3.5g水，将玻璃瓶替换为内胆为聚四氟乙烯的反应釜，放置的烘箱温度由95℃改为保持150℃，烘箱中95℃保持时间由4h改为12h，取出得到均一的5％质量分数聚合物溶液，热处理温度改为130℃，其余步骤与实施例5A相同。
实施例8A
按照实施例5A的方法，将加入3.5g质量分数为25％氨水和91.5g水替换为加入40g质量分数为25％氨水和55g水，玻璃瓶放置的烘箱温度由95℃改 为保持20℃，保持时间由4h改为0.5h，将实施例1A中热处理温度改为200℃，其余步骤与实施例5A相同。
实施例所得气凝胶循环效率测试方法以及气凝胶的回收方法(回收实施例A)
本发明耐水性马来酰亚胺基气凝胶称重得质量m1，向密闭带盖玻璃瓶中将其加入到91.5g水，再加入3.5g质量分数为25％氨水，并将5g(即m1)耐水性马来酰亚胺气凝胶加入到瓶中，将密闭带盖玻璃瓶盖旋紧后放入烘箱中保持95℃2小时得到均一的回收聚合物溶液。将聚合物溶液倒入6个模具中，每个模具倒入15ml溶液，并置于-30℃冰箱冷冻2小时，将冷冻好的样品转移到冷冻干燥机中冷冻干燥72小时后，取出得到的回收水溶性聚合物；将回收水溶性聚合物置入恒温容器中于180℃进行热处理2h，以脱水脱氨得到回收耐水性马来酰亚胺基气凝胶(即本发明中的回收聚合物气凝胶)。
称得回收耐水性马来酰亚胺基气凝胶质量为m2，回收效率为m2/m1*100％。
其中，实施例1A中的耐水性马来酰亚胺基气凝胶(聚合物气凝胶)经一次回收后的性能见表1A、表2A，对应样品名：实施例1A(回收1)，回收后的气凝胶再次进行一次上述回收，对应样品名命名为实施例1A(回收2)。
经验证，本发明中的实施例1A中聚合物气凝胶(马来酰亚胺基气凝胶)耐热性较好，玻璃化转变温度在250℃附近，分解温度在300℃附近，经过回收的该聚合物所制备的气凝胶耐热性要高于回收前的，证明了气凝胶回收前后聚合物均具有良好的耐热性，回收过程绿色环保。
测试例
实施例1A-6A及对比例1A-4A所制备气凝胶水溶性测试结果列于表1A，实施例1A-8A所制备的气凝胶的水接触角、循环效率、导热系数和密度测试结果列于表2A；对比例3A、实施例1A及实施例1A回收所得气凝胶红外光 谱测试曲线示于图1，对实施例及对比例的核磁测试示于图2，实施例1A所得气凝胶孔结构的扫描电子显微镜照片示于图3。从图1的气凝胶红外光谱测试曲线和图2的气凝胶核磁共振氢谱曲线可以确定聚合物气凝胶结构中，有马来酰亚胺结构的存在。
表1A
表2A


注：表2A中马来酰亚胺化率，即为以聚合物气凝胶中含马来酸酐基团的
结构单元和含马来酰亚胺基团的结构单元的总摩尔量为100％计，所述含马来酰亚胺基团的结构单元的摩尔比例。
通过表1A的实施例1A-6A及对比例1A-4A的测试结果对比表明，本发明所制备的气凝胶是耐水疏水的，通过氢氧化钠等非挥发性碱无法制备出疏水耐水气凝胶，氨水无法溶解氮苯基马来酰亚胺，同样无法直接溶于氨水制备疏水气凝胶。
通过表2A实施例1A-6A的水接触角、循环效率、导热系数和密度测试结果可以看出，气凝胶导热系数和密度较低，可以直接替代现有的低密度保温材料使用，由于气凝胶样品循环效率极高，因此更为绿色环保。其疏水性较好，可作为油水分离材料使用，由于其表面的多孔结构(图3)，气凝胶可以作为载体，负载如有机相变材料、催化剂等，亦可作为过滤材料使用。经检测，实施例7A、实施例8A中的聚合物气凝胶的水接触角、循环效率、导热系数和密度测试结果与实施例5A接近。
制备例1B
本发明实施例中聚合物制备：将500ml乙酸异戊酯置于1000ml三口烧瓶， 通入氮气30min除去氧气，将24.5g马来酸酐和26g苯乙烯加入烧瓶中。待完全溶解后，加入0.4g偶氮二异丁腈，将水浴锅温度升温至70℃，反应7h。反应后在10000r下离心10min，除去上清液，加入500ml甲醇，搅拌0.5小时，离心后去除去上清液，重复两次，然后140℃真空干燥24h，得到苯乙烯马来酸酐共聚物。
实施例1B
取91.5g水加入到带盖玻璃瓶中，再加入3.5g质量分数为25％的氨水和5g马来酸酐-苯乙烯共聚物，将玻璃瓶盖旋紧后放入烘箱中保持95℃，4小时后取出得到均一的5％质量分数聚合物溶液。
将15ml聚合物溶液倒入底部是封闭的筒状铝箔间隔层内，将10mL圆柱状玻璃小瓶(作为模具)固定于铝箔间隔层中心位置，玻璃小瓶四周和底部距离铝箔间隔层内壁的距离约9mm，保持玻璃瓶顶部大约高于溶液1mm，再将铝箔间隔层固定于装有20ml聚合物溶液的50ml(筒状)烧杯(作为预冷冻容器)的中心位置，间隔层底部距离烧杯约5mm，置于-30℃冰箱冷冻2小时，将冷冻好的样品转移到冷冻干燥机中(于-30℃以下，10Pa以下)冷冻干燥72小时后，取出得到的水溶性聚合物。
将水溶性聚合物置入烘箱中180℃进行热处理2h，以脱水脱氨使得内外层均得到马来酰亚胺系聚合物气凝胶(即本发明中的聚合物气凝胶)。
通过红外光谱测试和核磁共振氢谱测试确定聚合物气凝胶结构中，有马来酰亚胺结构的存在。经检测，以聚合物气凝胶中含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元的总摩尔量为100％计，所述含马来酰亚胺基团的结构单元的摩尔比例为43.6％；该聚合物气凝胶的水接触角为138.1°，导热系数为0.0362W/(m·k)，密度为72.3Kg/m3。
将11ml十二烷相变材料注入到内层的气凝胶至充满倒置并擦拭气凝胶相变复合材料表面的过量的相变材料，得到马来酰亚胺系共聚物气凝胶相变蓄 冷材料。
在使用时，疫苗等可以放置在玻璃瓶中。
实施例2B
取91.5g水加入到带盖玻璃瓶中将其，再加入3.5g质量分数为25％的氨水和5g马来酸酐-苯乙烯共聚物，将玻璃瓶盖旋紧后放入烘箱中保持95℃，4小时后取出得到均一的5％质量分数聚合物溶液。
将15ml聚合物溶液倒入底部是铜材质的聚四氟乙烯的筒状容器(容量为25mL)中，将10mL圆柱状玻璃小瓶(作为模具)固定于聚四氟乙烯的筒状容器中心，玻璃小瓶四周及底部距离聚四氟乙烯筒状容器的内壁的距离约9mm，保持玻璃瓶顶部大约高于溶液1mm，再将聚四氟乙烯筒状容器置于浸入液氮的铜柱上，待冷冻充分后，取下冷冻好的聚合物溶液的冰柱转移到筒状铝箔间隔层内，再将铝箔间隔层固定于装有20ml聚合物溶液的50ml筒状烧杯(作为预冷冻容器)的中心位置，间隔层底部距离烧杯约5mm，置于-30℃冰箱冷冻2小时，将冷冻好的样品转移到冷冻干燥机中(于-30℃以下，10Pa以下)冷冻干燥72小时后，取出得到的水溶性聚合物。
将水溶性聚合物置入烘箱中180℃进行热处理2h，以脱水脱氨使得内外层均得到马来酰亚胺系聚合物气凝胶，且内层马来酰亚胺系聚合物气凝胶为各向异性的气凝胶。
将11ml十二烷相变材料注入到内层的气凝胶至充满倒置并擦拭气凝胶相变复合材料表面的过量的相变材料，得到马来酰亚胺系共聚物气凝胶相变蓄冷材料。
实施例3B
将实施例1B中，聚合物溶液制备过程中步骤改变为，取94.9g水加入到带盖玻璃瓶中，再加入2.1g质量分数为25％的氨水和3g马来酸酐-苯乙烯共 聚物，将玻璃瓶盖旋紧后放入烘箱中保持95℃，4小时后取出得到均一的3％质量分数聚合物溶液，其他制备步骤与实施例1B相同，其中，十二烷的加入量为11ml。
实施例4B
将实施例2B中的十二烷替换为十四烷，其他制备步骤与实施例2B相同。
实施例5B
取80g水加入到内胆为聚四氟乙烯的反应釜，再加入3.5g质量分数为25％的氨水和5g马来酸酐异丁烯共聚物(可乐丽ISOBAM-08，分子量约为30万)，将反应釜密闭后放入烘箱中保持95℃，4小时后取出得到均一的聚合物溶液，室温下晾干得含有马来酰胺酸、马来酸铵基团的聚合物。
取1g上述聚合物放入在带盖玻璃瓶中，加入98.96g水，再加入0.04g质量分数为25％的氨水，将玻璃瓶盖旋紧后放入烘箱中保持20℃，0.5小时后取出得到均一的1％质量分数聚合物溶液。
将15ml聚合物溶液倒入底部是封闭的筒状铝箔间隔层内，将10mL圆柱状玻璃小瓶(作为模具)固定于铝箔间隔层中心位置，玻璃小瓶四周及底部距离铝箔间隔层内壁的距离约9mm，保持玻璃瓶顶部大约高于溶液1mm，再将铝箔间隔层固定于装有20ml 0.5％实施例1B中制备的聚合物溶液的50ml的聚四氟乙烯筒状容器中心位置，间隔层底部距离聚四氟乙烯筒状容器底部约5mm，并将其放置于液氮浴中的铜柱上。待预冻完成后，放入冷冻干燥机中，(-30℃以下，10Pa以下)冷冻干燥72小时后，得到各向异性的水溶性聚合物，将水溶性聚合物置入烘箱中130℃进行热处理2h，以脱水脱氨得到马来酰亚胺系聚合物气凝胶。将11ml十二烷相变材料注入到内层的气凝胶至充满倒置并擦拭气凝胶相变复合材料表面的过量的相变材料，得到马来酰亚胺系共聚物气凝胶相变蓄冷材料。
测试得泄漏量、相变温度和相变潜热与实施例2B接近。
实施例6B
取80g水加入到内胆为聚四氟乙烯的反应釜，再加入3.5g质量分数为25％的氨水和5g马来酸酐异丁烯共聚物(可乐丽ISOBAM-08，分子量约为30万)，将反应釜密闭后放入烘箱中保持95℃，4小时后取出得到均一的聚合物溶液，室温下晾干得含有马来酰胺酸、马来酸铵基团的聚合物。
取91.5g水加入到带盖玻璃瓶中将其，再加入3.5g质量分数为25％的氨水和上述所得的5g含有马来酰胺酸、马来酸铵基团的聚合物，将玻璃瓶盖旋紧后放入烘箱中保持150℃，10小时后取出得到均一的5％质量分数的共聚物水溶液。
将实施例2B中15ml聚合物溶液替换为本实施例中的上述5％共聚物溶液，其他制备步骤与实施例2B相同。
对脱水脱氨得到马来酰亚胺系聚合物气凝胶进行检测，之后按照实施例2B的步骤注入相变材料。
通过红外光谱测试和核磁共振氢谱测试确定聚合物气凝胶结构中，有马来酰亚胺结构的存在。经检测，以聚合物气凝胶中含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元的总摩尔量为100％计，所述含马来酰亚胺基团的结构单元的摩尔比例为38.7％；该聚合物气凝胶的水接触角为127.6°，导热系数为0.0369W/(m·k)，密度为73.1Kg/m3。
对相变材料测试得泄漏量、相变温度和相变潜热与实施例2B接近。
回收实施例B
取5g实施例2B中制备的气凝胶相变材料置于带盖密闭玻璃瓶中，再加入1g质量分数为25％的氨水和15g水，95摄氏度烘箱保持2h，得到液体(图6中的a)，使用分液漏斗分液得到回收聚合物水溶液(图6中的c)和相变材 料(图6中的b)。
将所得聚合物水溶液作为制备气凝胶的原材料、相变材料作为制备相变材料的原材料，按照实施例2B方法制备得到相变复合材料。
测试得泄漏量、相变温度和相变潜热与实施例2B接近。
表1B
由表1B可见，本发明中实施例中可回收蓄冷相变复合材料中相变材料吸附量较高，且相变材料的泄漏量更少，可广泛应用于在食品保鲜、冷链运输领域(例如疫苗、药品的冷链运输)等环节。
表2B

由表2B可见，本发明中的多孔气凝胶对相变材料造成的潜热损失很小，可制备储冷能力高、泄漏量低的相变复合材料。
应当注意的是，以上所述的实施例仅用于解释本发明，并不构成对本发明的任何限制。通过参照典型实施例对本发明进行了描述，但应当理解为其中所用的词语为描述性和解释性词汇，而不是限定性词汇。可以按规定在本发明权利要求的范围内对本发明作出修改，以及在不背离本发明的范围和精神内对本发明进行修订。尽管其中描述的本发明涉及特定的方法、材料和实施例，但是并不意味着本发明限于其中公开的特定例，相反，本发明可扩展至其他所有具有相同功能的方法和应用。
本说明书提到的所有出版物、专利申请、专利和其它参考文献全都通过引用并入本文。除非另有定义，本说明书所用的所有技术和科学术语都具有本领域技术人员常规理解的含义。在有冲突的情况下，以本说明书的定义为准。
当本说明书以词头“本领域技术人员公知”、“现有技术”或其类似用语来导出材料、物质、方法、步骤、装置或部件等时，该词头导出的对象涵盖本申请提出时本领域常规使用的那些，但也包括目前还不常用，却将变成本领域公认为适用于类似目的的那些。
在本申请文件中所披露的范围的端点和任何值都不限于该精确的范围或值，这些范围或值应当理解为包含接近这些范围或值的值。对于数值范围来说，各个范围的端点值之间、各个范围的端点值和单独的点值之间，以及单独的点值之间可以彼此组合而得到一个或多个新的数值范围，这些数值范围应被视 为在本文中具体公开。在下文中，各个技术方案之间原则上可以相互组合而得到新的技术方案，这也应被视为在本文中具体公开。
在本说明书的上下文中，除了明确说明的内容之外，未提到的任何事宜或事项均直接适用本领域已知的那些而无需进行任何改变。
而且，本文描述的任何实施方式均可以与本文描述的一种或多种其他实施方式自由结合，由此而形成的技术方案或技术思想均视为本发明原始公开或原始记载的一部分，而不应被视为是本文未曾披露或预期过的新内容，除非本领域技术人员认为该结合是明显不合理的。

Claims (29)

  1. 一种聚合物气凝胶，所述聚合物中含有含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元，其中所述马来酸酐基团指的是所述马来酰亚胺基团指的是
  2. 根据权利要求1所述的聚合物气凝胶，其特征在于：
    以含马来酸酐基团的结构单元和含马来酰亚胺基团的结构单元的总摩尔量为100％计，所述聚合物中含马来酰亚胺基团的结构单元的摩尔比例为5％-70％，优选为10％-60％；更优选为20％-50％。
  3. 根据权利要求1所述的聚合物气凝胶，其特征在于：
    所述聚合物衍生自含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料；优选地，所述聚合物原料是包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共聚物；更优选地，所述烯烃单体为α-甲基苯乙烯、苯乙烯、异丁烯中的至少一种。
  4. 根据权利要求1所述的聚合物气凝胶，其特征在于：
    所述聚合物气凝胶能够溶于0-150℃的氨水中，形成聚合物水溶液；优选地，所述聚合物水溶液经预冷冻、冷冻干燥、热处理，能够回收得到聚合物气凝胶；和/或，
    所述聚合物气凝胶的导热系数为0.025-0.05W/(m·k)，优选为0.027-0.04W/(m·k)；和/或，
    所述聚合物气凝胶的密度为10-100kg/m3，优选为15-75kg/m3；和/或，
    所述聚合物气凝胶为三维多孔材料。
  5. 根据权利要求1所述的聚合物气凝胶，其特征在于：
    所述聚合物气凝胶的静态水接触角在100°以上，优选110°以上，更优选在135°以上；和/或，
    所述聚合物气凝胶不溶于水，优选地，将所述聚合物气凝胶置于20-40℃水中浸泡24h，优选浸泡72h，更优选浸泡168h后，不会溶解形成聚合物的水溶液。
  6. 根据权利要求1-5之一所述的聚合物气凝胶，其特征在于：
    所述聚合物气凝胶通过将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭情况下发生反应，再经预冷冻、冷冻干燥、热处理脱水脱氨后制备得到。
  7. 一种权利要求1-6之一所述的聚合物气凝胶的制备方法，包括将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭条件下发生反应，再经预冷冻、冷冻干燥、热处理脱水脱氨，得到所述聚合物气凝胶。
  8. 根据权利要求7所述的制备方法，其特征在于包括以下具体步骤：
    (1)将所述聚合物原料与氨水在密闭条件下发生反应，得到聚合物水溶液；
    (2)将步骤(1)得到的聚合物水溶液先进行预冷冻，再经冷冻干燥，得到水溶性聚合物；
    (3)将步骤(2)得到的水溶性聚合物进行热处理，得到所述聚合物气凝 胶。
  9. 根据权利要求8所述的制备方法，其特征在于：
    步骤(1)中：
    以反应体系的总质量为100％计，聚合物原料用量的质量分数为0.1％-30％，优选为0.5％-10％，更优选为1％-5％，以氨水中氨的质量计，氨用量的质量分数为0.0001％-30％，优选为0.01％-10％，更优选为0.1％-1％，其余组分为水；
    和/或，反应的条件包括：
    反应温度为0-200℃，优选为50-150℃，更优选为80-100℃；和/或，反应时间为0.01-100h，优选为0.5-10h，更优选为1-5h。
  10. 根据权利要求8所述的制备方法，其特征在于：
    步骤(2)中：
    将步骤(1)得到的聚合物水溶液于模具中预冷冻，优选地，所述预冷冻时溶液的各个方向冷源温度相同或不同；和/或，
    冷冻干燥的条件包括：温度优选为(-10)℃以下；真空度优选为1000Pa以下。
  11. 根据权利要求8所述的制备方法，其特征在于：
    步骤(3)中热处理的条件包括：
    温度为100-300℃，优选为130-200℃，更优选为150-190℃，和/或，时间为0.1-10h，优选为0.5-3h，更优选为1-2h。
  12. 根据权利要求7-11之一所述的制备方法，其特征在于：
    所述聚合物原料是包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与烯烃单体的共聚物；优选地，所述烯烃 单体包括α-甲基苯乙烯、苯乙烯、异丁烯中的至少一种。
  13. 根据权利要求7-11之一所述的制备方法，其特征在于：
    所述聚合物原料为苯乙烯马来酸酐共聚物、苯乙烯马来酸酐乙烯基硅油共聚物、马来酸酐异丁烯共聚物中的至少一种；优选地，所述聚合物原料为苯乙烯马来酸酐共聚物、马来酸酐异丁烯共聚物中的至少一种。
  14. 一种聚合物气凝胶的回收方法，所述聚合物气凝胶为权利要求1-6之一所述的聚合物气凝胶或权利要求7-13之一所述的制备方法制备得到的聚合物气凝胶，所述回收方法包括将所述聚合物气凝胶和/或包含有所述聚合物气凝胶的材料与氨水于密闭条件下混合反应，直至得到含有回收聚合物的水溶液，任选地除去不溶物，得到回收聚合物的水溶液；
    优选地，混合反应的温度为0-200℃，优选为50-150℃，更优选为80-100℃，和/或，混合反应的时间为0.01-100h，优选为0.5-10h，更优选为1-5h。
  15. 根据权利要求14所述的回收方法，其特征在于：
    所述回收方法还包括将回收聚合物的水溶液经预冷冻、冷冻干燥、热处理，回收得到聚合物气凝胶；优选地，
    所述预冷冻时溶液的各个方向冷源温度相同或不同；和/或，
    冷冻干燥的条件包括：温度为(-10)℃以下；和/或，真空度为1000Pa以下；和/或，
    热处理的条件包括：
    温度为100-300℃，优选为130-200℃，更优选为150-190℃，和/或，时间为0.1-10h，优选为0.5-3h，更优选为1-2h。
  16. 根据权利要求14或15所述的回收方法得到的回收聚合物气凝胶。
  17. 权利要求1-6之一所述的聚合物气凝胶、权利要求7-13之一所述的制备方法制备得到的聚合物气凝胶或者权利要求16所述的回收聚合物气凝胶在作为多孔材料优选作为载体、过滤材料、用于吸附有机相变材料，或者作为油水分离材料、保温材料中的应用。
  18. 一种可回收蓄冷相变复合材料，包括聚合物气凝胶和负载于所述聚合物气凝胶中的相变材料；其中，所述聚合物气凝胶为权利要求1-6之一所述的聚合物气凝胶、权利要求7-13之一所述的制备方法制备得到的聚合物气凝胶或者权利要求16所述的回收聚合物气凝胶。
  19. 根据权利要求18所述的可回收蓄冷相变复合材料，其特征在于：
    以所述可回收蓄冷相变复合材料的总质量为100％计，所述聚合物气凝胶的含量为2％-20％，优选为4％-10％，所述相变材料的含量为80％-98％，优选为90％-96％；和/或，
    所述相变材料为有机相变材料，优选地，所述有机相变材料的相变温度为(-10)-30℃，和/或，相变潜热为55-280J/g；更优选地，所述有机相变材料为烷烃类有机相变材料；最优选为十烷、十二烷、十四烷中的至少一种；和/或，
    在所述相变材料为液态的温度条件下，所述可回收蓄冷相变复合材料中相变材料泄漏量小于10wt％，优选小于5wt％，更优选小于2wt％。
  20. 根据权利要求18所述的可回收蓄冷相变复合材料，其特征在于：
    所述聚合物气凝胶为各向异性气凝胶，优选为预冷冻时单向冷源温度不同所得的各向异性气凝胶；和/或，
    所述聚合物气凝胶能够溶于0-150℃的氨水中形成含有聚合物的溶液，优选地，含有聚合物的溶液经预冷冻、冷冻干燥、热处理，能够回收得到聚合物气凝胶；和/或，
    所述聚合物气凝胶的密度为100kg/m3以下，优选为15-80kg/m3。
  21. 根据权利要求18-20之一所述的可回收蓄冷相变复合材料，其特征在于：
    所述聚合物气凝胶通过将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭情况下发生反应，再经预冷冻、冷冻干燥、热处理脱水脱氨后制备得到；优选地，
    预冷冻时溶液的各个方向冷源温度相同或不同，更优选地，预冷冻时溶液的各个方向冷源温度不同，得到各向异性气凝胶；
    最优选地，所述预冷冻溶液单向冷源温度不同，得到各向异性气凝胶。
  22. 一种权利要求18-21之一所述的可回收蓄冷相变复合材料的制备方法，包括将所述相变材料负载在所述聚合物气凝胶中。
  23. 根据权利要求22所述的制备方法，其特征在于所述制备方法包括以下步骤：
    (1)将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭情况下发生反应，得到聚合物水溶液；
    (2)将步骤(1)得到的聚合物水溶液先进行预冷冻，再经冷冻干燥，得到水溶性聚合物；
    (3)将步骤(2)得到的水溶性聚合物进行热处理，得到所述聚合物气凝胶；
    (4)将所述相变材料负载在所述聚合物气凝胶中。
  24. 根据权利要求23所述的制备方法，其特征在于：
    步骤(1)中以反应体系的总质量为100％计，聚合物原料用量的质量分数为0.1％-30％，优选为1％-10％，更优选为2％-5％，以氨水中氨的质量计，氨用量的质量分数为0.001％-30％，优选为0.01％-10％，更优选为0.1％-1％，其余组分为水；和/或，
    在预冷冻阶段，步骤(1)得到的聚合物水溶液的各个方向冷源温度不同，优选单向冷源温度不同；和/或，
    在步骤(2)进行预冷冻前，将模具插入所述步骤(1)得到的聚合物水溶液中，并在步骤(3)的热处理后，任选地取出模具，得到具有空腔的聚合物气凝胶，步骤(4)中将相变材料负载至所述聚合物气凝胶中。
  25. 一种具有实时温度监测功能的可回收蓄冷相变材料，所述可回收蓄冷相变材料具有层结构，包括由权利要求18-21之一所述的可回收蓄冷相变复合材料或者权利要求22-24之一所述的制备方法制备得到的可回收蓄冷相变复合材料形成的内层，和第二聚合物气凝胶形成的外层。
  26. 根据权利要求25所述的具有实时温度监测功能的可回收蓄冷相变材料，其特征在于：
    所述内层的厚度为3mm以上，所述外层的厚度为5mm以上；和/或，
    所述内层与所述外层之间还具有间隔层；和/或，
    所述内层设置有空腔；和/或，
    所述第二聚合物气凝胶具有光致发光性能且能够随着温度的变化光信号发生变化；优选地，所述第二聚合物气凝胶选自根据权利要求18-21之一所述的可回收蓄冷相变复合材料中具有光致发光性能且能够随着温度的变化光信号发生变化的聚合物气凝胶的至少一种，且第二聚合物气凝胶与所述的可回收蓄冷相变复合材料中的聚合物气凝胶可以相同或不同；
    更优选地，所述第二聚合物为包括马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐中的一种或几种的聚合单体与苯乙烯形成的共聚物。
  27. 一种权利要求25或26所述的具有实时温度监测功能的可回收蓄冷相变材料的制备方法，其特征在于包括以下步骤：
    (1)将含有含马来酸酐、马来酰亚胺、马来酸及铵盐、马来酰胺酸及铵盐基团的结构单元中的一种或几种的聚合物原料与氨水在密闭情况下发生反应，得到聚合物水溶液；
    (2)将聚合物水溶液置于间隔层内侧空间或间隔层内侧与模具之间的空间，然后进行预冷冻，再经冷冻干燥，得到水溶性聚合物；
    (3)将步骤(2)得到的水溶性聚合物进行热处理，任选地取出模具，得到具有空腔的聚合物气凝胶；
    (4)将相变材料负载在步骤(3)得到的聚合物气凝胶中，形成所述可回收蓄冷相变材料的内层；
    其中，在步骤(2)、步骤(3)、步骤(4)的步骤中和/或所述步骤之间和/或步骤(4)之后将第二聚合物气凝胶包覆在间隔层外侧，从而形成所述可回收蓄冷相变材料的外层；
    或者，在步骤(2)中将含有第二聚合物气凝胶的水溶液和/或第二聚合物水溶液置于间隔层外侧空间，从而形成所述可回收蓄冷相变材料的外层；优选地，第二聚合物水溶液与步骤(1)的聚合物水溶液相同。
  28. 根据权利要求27所述的制备方法，其特征在于：
    内层的聚合物水溶液中聚合物含量的质量分数为0.1％-30％，优选1％-10％，和/或，第二聚合物气凝胶的水溶液和/或第二聚合物水溶液的中第二聚合物含量的质量分数各自为0.1％-30％，优选0.5％-10％，更优选1％-5％；和/或，
    步骤(2)中，在预冷冻阶段，步骤(1)得到的聚合物水溶液的各个方向冷源温度不同，优选单向冷源温度不同。
  29. 权利要求18-21之一所述的可回收蓄冷相变复合材料或者权利要求22-24之一所述的制备方法制备得到的可回收蓄冷相变复合材料、权利要求25或26所述的具有实时温度监测功能的可回收蓄冷相变材料或者权利要求27或28所述的制备方法制备得到的具有实时温度监测功能的可回收蓄冷相变材料在食品保鲜、冷链运输领域中的应用。
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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101171075A (zh) * 2005-04-08 2008-04-30 里尔科学技术大学 可官能化整体材料
US20110245361A1 (en) * 2010-03-30 2011-10-06 Samsung Electronics Co., Ltd Organic aerogel and composition for the organic aerogel
US9650487B1 (en) * 2014-06-20 2017-05-16 The United States Of America As Represented By The Administrator Of National Aeronautics And Space Administration Polyalkylene imide aerogels and processes for making the same
CN107417961A (zh) * 2017-07-28 2017-12-01 四川大学 一种各向异性聚酰亚胺气凝胶材料及其制备方法
CN109912833A (zh) * 2019-02-11 2019-06-21 东华大学 一种聚酰亚胺气凝胶及其制备方法
CN111808372A (zh) * 2019-04-11 2020-10-23 中国石油化工股份有限公司 一种共聚物作为光稳定剂的用途和其复合光稳定剂及制法和应用
US20210189091A1 (en) * 2017-12-05 2021-06-24 Blueshift Materials, Inc. Thermally treated polyamic amide aerogel

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101171075A (zh) * 2005-04-08 2008-04-30 里尔科学技术大学 可官能化整体材料
US20110245361A1 (en) * 2010-03-30 2011-10-06 Samsung Electronics Co., Ltd Organic aerogel and composition for the organic aerogel
US9650487B1 (en) * 2014-06-20 2017-05-16 The United States Of America As Represented By The Administrator Of National Aeronautics And Space Administration Polyalkylene imide aerogels and processes for making the same
CN107417961A (zh) * 2017-07-28 2017-12-01 四川大学 一种各向异性聚酰亚胺气凝胶材料及其制备方法
US20210189091A1 (en) * 2017-12-05 2021-06-24 Blueshift Materials, Inc. Thermally treated polyamic amide aerogel
CN109912833A (zh) * 2019-02-11 2019-06-21 东华大学 一种聚酰亚胺气凝胶及其制备方法
CN111808372A (zh) * 2019-04-11 2020-10-23 中国石油化工股份有限公司 一种共聚物作为光稳定剂的用途和其复合光稳定剂及制法和应用

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
YAO, YUAN ET AL.: "Preparation and application of recyclable polymer aerogels from styrene-maleicanhydride alternating copolymers", CHEMICAL ENGINEERING JOURNAL,, vol. 455, 14 November 2022 (2022-11-14), XP087259101, DOI: 10.1016/j.cej.2022.140363 *
ZHANG ZHONGXIN, PAN YUELEI, GONG LUNLUN, YAO XIANDONG, CHENG XUDONG, DENG YURUI: "Mechanically strong polyimide aerogels cross-linked with low-cost polymers", RSC ADVANCES, ROYAL SOCIETY OF CHEMISTRY, GB, vol. 11, no. 18, 15 March 2021 (2021-03-15), GB , pages 10827 - 10835, XP093147160, ISSN: 2046-2069, DOI: 10.1039/D0RA10633J *

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