CN110655790A - Production method of polyimide foam material - Google Patents
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- CN110655790A CN110655790A CN201910924169.9A CN201910924169A CN110655790A CN 110655790 A CN110655790 A CN 110655790A CN 201910924169 A CN201910924169 A CN 201910924169A CN 110655790 A CN110655790 A CN 110655790A
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- 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
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
- C08J9/06—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent
- C08J9/08—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent developing carbon dioxide
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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
- C08G73/1003—Preparatory processes
- C08G73/1035—Preparatory processes from tetracarboxylic acids or derivatives and diisocyanates
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- 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
- C08J2203/00—Foams characterized by the expanding agent
- C08J2203/02—CO2-releasing, e.g. NaHCO3 and citric acid
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- 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
- C08J2379/00—Characterised by the use 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 C08J2361/00 - C08J2377/00
- C08J2379/04—Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors
- C08J2379/08—Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
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Abstract
The invention discloses a production method of a polyimide foam material, which comprises the following steps: adding a polar solvent and fatty alcohol into a dibasic anhydride serving as a substrate to perform esterification reaction, then adding the dibasic anhydride, an initiator, a catalyst and a surfactant to prepare a foaming precursor, then adding isocyanate to perform foaming, and curing by adopting a two-step curing method after molding and demolding to prepare the polyimide foam material. According to the preparation method, the binary anhydride is used as a substrate, the isocyanate is added for foaming, and the polyimide is prepared in a microwave and vacuum resistance furnace heating and curing manner, so that the preparation process is simplified, the production cost of the foam material is reduced, the imidization conversion rate is improved, the industrial production is easy, and the popularization and the application are convenient; the prepared foam material has the characteristics of low heat conductivity coefficient, excellent flame retardant property, small moisture absorption rate and the like, is suitable for the fields of aerospace and military ships, is also suitable for the field of civil building heat insulation materials, and has good application prospect.
Description
Technical Field
The invention belongs to the technical field of high polymer materials, and particularly relates to a production method of a polyimide foam material.
Background
Polyimide is a polymer with excellent heat resistance, has good mechanical and electrical properties, is resistant to radiation and corrosion, and is widely applied to the fields of aerospace, military, electronics and the like. The polyimide material with the foam structure not only keeps excellent performances of the original resin such as temperature resistance, flame retardance, water resistance, radiation resistance and the like, but also has outstanding wave-transmitting characteristics and comprehensive performances such as light weight, low heat conductivity coefficient, good heat insulation performance and the like, so that the polyimide material with the foam structure is widely applied to the field of military equipment.
The polyimide foam is successfully developed by the NASA, Langley research center and the UnitikaAmerica company at the earliest, is used as a heat insulation material for the bulkhead of an aerospace plane at the earliest and is popularized to the fields of planes, ships, vehicles and the like. Solimide polyimide foam plastics produced by American InspecFoam company utilize the high and low temperature resistance, flame retardance and self-extinguishing characteristics of Solimide to replace phenolic aldehyde and polyurethane foam, are designated as heat insulation materials of navy ships by the American department of defense, and are used for improving the environmental adaptability and safety of warships. In addition, it is also used in civil ships such as luxury yachts, yachts and lng ships.
Currently, the preparation of polyimide foams is generally divided into a one-step process and a two-step process. Wherein, the one-step method is to foam at one time through polycondensation reaction, and gas generated in the reaction is used as a foaming agent to foam to form polyimide foam; the method has simple preparation process and short period, is easy to realize industrial large-scale production, and the prepared foam has uniform aperture and stable performance. But the foaming process has higher operation requirement, difficult operation and low imidization degree. The two-step method is that firstly aromatic dianhydride or aromatic acid ester reacts with diamine to prepare polyester ammonium salt precursor powder, then the polyester ammonium salt precursor powder synthesized in the first step is placed in a specific mould, and the polyimide foam plastic is prepared by microwave or heating foaming; the method can obtain high-density foam plastics, and the prepared foam plastics have good comprehensive performance. However, the preparation process is complex, the cost is high, the prepared foam has uneven pore size and more defects, and the low-density foam material is difficult to produce.
1. The patent application CN201710035692.7 discloses a reinforced and toughened self-curing rigid polyimide foam material and a preparation method thereof, wherein aromatic dianhydride, furfuryl alcohol, fatty alcohol, a catalyst, a surfactant, a modifier and the like are mixed with a modified black material for foaming to obtain the reinforced and toughened self-curing rigid polyimide foam, and the density range is 76-113Kg/m3(ii) a Tensile strength: 2.56-3.23 MPa; breaking strength: 379-873N/m; temperature resistance in long-term operation: 380 ℃ and 450 ℃. The patent application adds glass microspheres, glass fibers and the like, and can increase the strength and toughness of products, but also increase the complexity of the production process and is more difficult to control.
2. Patent application CN201910036701.3 discloses a preparation method of a high-performance rigid polyimide heat-insulating sound-absorbing foam, which comprises the following steps: under the protection of nitrogen, polyisocyanate is dissolved in polar solvent, then aromatic anhydride is added, then surfactant is added, standing, polymerization and thickening are carried out for 5-10 days, and then microwave and high-temperature oven curing are carried out to obtain foam material, wherein the density of the polyimide foam material obtained by the method is 124-3Within the range; compressive strength: 1.2-5.4 MPa; glass transition temperature: 330 ℃ to 342 ℃; 10% decomposition temperature: 532-550 ℃; average sound absorption coefficient: 0.59-0.65. However, the free foaming time of the patent application is too long, the high-temperature curing is complex, the later energy consumption is serious, and the influence on the industrialization efficiency and the cost is large.
3. Patent application CN201610339855.6 discloses a polyimide foam material, which is obtained by taking aromatic dicarboxylic anhydride and aromatic diamine as main raw materials and modifying blocked isocyanate; reacting aromatic dicarboxylic anhydride in a mixed solvent of a polar solvent and micromolecular alcohol, adding aromatic diamine to continuously react to form an amine salt compound, sequentially adding blocked isocyanate, water, a silicone oil surfactant and the like to obtain a polyimide foam precursor solution, concentrating the polyimide foam precursor solution, cooling and crushing, foaming by using microwaves, and then further heating at high temperature to realize imidization to obtain the final polyimide foam material. The product performance of the invention is greatly improved compared with the isocyanate-based foam, and the process operation performance is better than that of polyimide foam prepared by a two-step method, thus the invention has good application prospect. However, the patent adopts modified blocked isocyanate, and cooling, crushing and foaming are carried out firstly, so that the two-step foaming method belongs to two-step foaming, increases the process procedures and process complexity, and is not beneficial to industrial production.
4. Patent application CN201110441923.7 discloses a preparation method of low density polyimide soft foam, comprising the following steps: (1) preparing powder A: mixing dibasic anhydride D1, deionized water and C1-C2 alkyl monohydric alcohol, reacting at 60-90 ℃ until the mixture is transparent, cooling to 25-55 ℃, adding diamine or diisocyanate DA1 with the same mole as the dibasic anhydride, reacting at the temperature of less than or equal to 40 ℃ for 30-120 minutes, cooling to room temperature, continuously stirring for 120 minutes to obtain liquid resin precursor polyamide-ester with the solid content of 55-65% and the viscosity of less than 10000cp, and drying and crushing in vacuum to obtain powder A; (2) preparing powder B: polymerizing dicarboxylic anhydride D2 and diamine DA2 to synthesize polyamide acid resin with the viscosity of 800-1500 p and the solid content of 15-40%, and drying, ring-closing and aging to obtain B powder with the Tg of more than 300 ℃; (3) foaming: and fully mixing the powder A and the powder B, foaming, closing a ring, and aging to obtain the multipurpose polyimide soft foam, wherein the mass percentage of the powder B in the powder A and the powder B is x, and x is more than 0 and less than or equal to 40%. However, the method adopts the dibasic anhydride or the diamine as one of the main raw materials, which increases the production cost, and the method adopts a two-step method to prepare the polyimide foam, which increases the process steps and is not beneficial to industrial production.
Therefore, the production method of the polyimide foam material has the advantages of low preparation cost, high imidization conversion rate, low heat conductivity coefficient, excellent flame retardant property, low moisture absorption rate and the like.
Disclosure of Invention
The invention provides a production method of a polyimide foam material to solve the technical problems.
In order to achieve the above purpose, the invention adopts the following technical scheme:
a method for producing a polyimide foam material, comprising the steps of: adding a polar solvent and fatty alcohol into a dibasic anhydride serving as a substrate to perform esterification reaction, then adding the dibasic anhydride, an initiator, a catalyst and a surfactant to prepare a foaming precursor, then adding isocyanate to perform foaming, and curing by adopting a two-step curing method after molding and demolding to prepare the polyimide foam material.
Further, the production method of the polyimide foam material comprises the following steps:
(1) preparation of an esterification solution: taking dibasic anhydride as a substrate, adding a polar solvent and fatty alcohol, mixing, uniformly stirring for esterification, and cooling to room temperature to obtain an esterified liquid;
(2) preparing a foaming precursor: adding dibasic anhydride, an initiator, a catalyst and a surfactant into the esterification solution obtained in the step (1), and uniformly stirring to obtain a foaming precursor;
(3) foaming and curing: and (3) adding isocyanate into the foaming precursor in the step (2) in a stirring state, uniformly stirring, quickly transferring into a forming die for forming, demolding, and then heating and curing by adopting a two-step curing method to obtain the polyimide foam material.
Further, in the step (1), the temperature of the esterification reaction is 40-70 ℃.
In step (1), the mass ratio of the dibasic anhydride, the polar solvent and the fatty alcohol is (3-10): 1-3).
Further, in the step (1), the dibasic anhydride is 3,3',4,4' -Benzophenone Tetracarboxylic Dianhydride (BTDA), 2,3,3',4' -benzophenone tetracarboxylic dianhydride (α -BTDA), 3,3',4,4' -biphenyl tetracarboxylic dianhydride (s-BPDA), 2,3',4,4' -biphenyl tetracarboxylic dianhydride (α -BPDA), 1,2,4, 5-pyromellitic dianhydride (PMDA), 3,3',4,4' -diphenyl ether tetracarboxylic dianhydride (ODPA), 2,3,3',4' -diphenyl ether tetracarboxylic dianhydride (α -ODPA), 3,3',4,4' -biphenyl sulfone tetracarboxylic dianhydride (DSDA), bisphenol A type diphenyl ether dianhydride (BPADA), 3,3',4,4' -diphenyl sulfide Tetracarboxylic Dianhydride (TDPA), 3, one or more than one of 3',4,4' -triphenyl diether tetracarboxylic dianhydride (HQDA).
Further, in the step (2), the mass ratio of the esterification liquid to the dibasic anhydride, the initiator, the catalyst and the surfactant is (40-100): 30-100): 1-3): 3-6.
Further, in the step (2), the foam stabilizer is one or more of polysiloxane, tetramethyl silicone oil, AK series silicone oil (e.g. AK8803, AK8805), DC series silicone oil (e.g. DC19, DC198), silicone polyether copolymer, silicone.
Further, in step (3), the two-step curing method is: the first step is microwave heating, the temperature of a system is controlled to be 50-200 ℃, and the time is 10-60 min; and in the second step, a vacuum resistance furnace is adopted for heating, the heating temperature is 150-300 ℃, the time is 0.5-4 h, and the vacuum degree is 0.5-5 MPa.
Further, in the step (3), the isocyanate is phenyl diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, polyphenyl polymethylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, tetramethylxylylene diisocyanate, 4' -diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, 3' -dimethoxy-4, 4' -diphenyl diisocyanate, methylcyclohexane diisocyanate, cyclohexyldimethylene diisocyanate, methyl formate pentamethylene diisocyanate, diphenylmethane-4, 4' -diisocyanate, 1, 5-diisocyanatonaphthalene, naphthalene, One or more than one of dimethyl biphenyl diisocyanate.
Further, in the steps (1), (2) and (3), the rotation speed of the stirring is 900-1000 r/min, and the time is 35-55 min.
Further, in the step (1), the aliphatic alcohol is one or more of methanol, ethanol, ethylene glycol, propanol, isopropanol, n-butanol, n-octanol and dodecanol.
Further, in the step (1), the polar solvent is one or more of tetrahydrofuran, 2-chloropyridine, 2, 6-dichloropyridine, dimethyl sulfoxide, N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, propylene glycol methyl ether and dipropylene glycol dimethyl ether.
Further, in the step (2), the catalyst is one or more of diethanolamine, triethanolamine, triethylene diamine, dimethyl ethanolamine, dipropylene glycol, triethylene diamine, organic tin, stannous octoate, dibutyltin diacetate and dibutyltin dilaurate.
Further, in step (2), the initiator is water.
The reaction principle of the application is as follows: carrying out esterification reaction on binary anhydride and fatty alcohol in a polar solvent to obtain a diacid diester solution; in the foaming and curing process: after adding isocyanate into the foaming precursor, generating polyesteramide ester by a part of isocyanate and diacid diester reacted in the step (1) under the action of a catalyst and an initiator, and then curing imide at high temperature for cyclization to obtain polyimide and carbon dioxide (CO 2); the other part of isocyanate reacts with the initiator in the foaming precursor to generate CO2 and amino; the generated CO2 is used as a main foaming source to foam and mold the polyimide.
Due to the adoption of the technical scheme, the invention has the following beneficial effects:
(1) according to the invention, after a foaming precursor is prepared by taking binary anhydride as a substrate, isocyanate is added for foaming, and polyimide is prepared in a heating and curing mode of mutual matching of microwave and vacuum resistance furnace, the prepared polyimide foam material has the characteristics of low heat conductivity coefficient, excellent flame retardant property, small moisture absorption rate and the like, and the prepared polyimide foam material is not only suitable for the fields of aerospace and military ships, but also suitable for the field of civil building heat insulation materials, and has good application prospect.
(2) The preparation method is simple in preparation process, low in cost, high in imidization conversion rate, easy for industrial production and convenient for popularization and application.
(3) The invention adopts a one-step method to prepare the polyimide foam, improves the defect of low imidization conversion rate of the original one-step method, and improves the synthesis efficiency.
(4) The invention adopts a two-step method for curing, wherein the microwave heating curing effect is to promote the reaction, the second curing step is to heat under the high-pressure condition of a vacuum resistance furnace to stabilize the bubbles, and after the bubbles are stabilized, the pressure is slowly released, and the small molecule gas is released by heating under the vacuum condition.
Detailed Description
The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.
Example 1
A method for producing a polyimide foam material, comprising the steps of: taking dibasic anhydride as a substrate, adding a polar solvent and fatty alcohol for esterification reaction, then adding the dibasic anhydride, an initiator, a catalyst and a surfactant to prepare a foaming precursor, then adding isocyanate for foaming, and curing by adopting a two-step curing method after molding and demolding to prepare the polyimide foam material, wherein the method specifically comprises the following steps:
(1) preparation of an esterification solution: taking dibasic anhydride as a substrate, adding a polar solvent and fatty alcohol, mixing, uniformly stirring for esterification, and cooling to room temperature to obtain an esterified liquid;
(2) preparing a foaming precursor: adding dibasic anhydride, an initiator, a catalyst and a surfactant into the esterification solution obtained in the step (1), and uniformly stirring to obtain a foaming precursor;
(3) foaming and curing: and (3) adding isocyanate into the foaming precursor in the step (2) in a stirring state, uniformly stirring, quickly transferring into a forming die for forming, demolding, and then heating and curing by adopting a two-step curing method to obtain the polyimide foam material.
Further, in the step (1), the temperature of the esterification reaction is 40-70 ℃; the mass ratio of the dibasic anhydride to the polar solvent to the fatty alcohol is (3-10) to (1-3); the binary anhydride is one or more of 3,3',4,4' -benzophenone tetracarboxylic dianhydride, 2,3,3',4' -benzophenone tetracarboxylic dianhydride, 3,3',4,4' -biphenyl tetracarboxylic dianhydride, 2,3',4,4' -biphenyl tetracarboxylic dianhydride, 1,2,4, 5-pyromellitic dianhydride, 3,3',4,4' -diphenyl ether tetracarboxylic dianhydride, 2,3,3',4' -diphenyl ether tetracarboxylic dianhydride, 3,3',4,4' -biphenyl sulfone tetracarboxylic dianhydride, bisphenol A type diphenyl ether dianhydride, 3,3',4,4' -diphenyl sulfide tetracarboxylic dianhydride, and 3,3',4,4' -triphenyl diether tetracarboxylic dianhydride; the fatty alcohol is one or more of methanol, ethanol, ethylene glycol, propanol, isopropanol, n-butanol, n-octanol and dodecanol; the polar solvent is one or more of tetrahydrofuran, 2-chloropyridine, 2, 6-dichloropyridine, dimethyl sulfoxide, N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, propylene glycol methyl ether and dipropylene glycol dimethyl ether.
Further, in the step (2), the mass ratio of the esterification liquid to the dibasic anhydride, the initiator, the catalyst and the surfactant is (40-100): 30-100): 1-3): 3-6; the foam stabilizer is one or more of polysiloxane, tetramethyl silicone oil, AK series silicone oil, DC series silicone oil, silicone polyether copolymer, organic silicon and silicone; the catalyst is one or more of diethanolamine, triethanolamine, triethylene diamine, dimethylethanolamine, dipropylene glycol, triethylene diamine, organic tin, stannous octoate, dibutyltin diacetate and dibutyltin dilaurate; the initiator is water.
Further, in step (3), the two-step curing method is: the first step is microwave heating, the temperature of a system is controlled to be 50-200 ℃, and the time is 10-60 min; secondly, heating by adopting a vacuum resistance furnace at the temperature of 150-300 ℃ for 0.5-4 h and under the vacuum degree of 0.5-5 MPa; the isocyanate is phenyl diisocyanate, p-phenyl diisocyanate, diphenylmethane diisocyanate, polyphenyl polymethylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, tetramethylbenzene dimethylene diisocyanate, 4,4 '-diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, 3' -dimethoxy-4, 4 '-diphenyl diisocyanate, methylcyclohexane diisocyanate, cyclohexyldimethylene diisocyanate, methyl formate pentamethylene diisocyanate, diphenylmethane-4, 4' -diisocyanate, 1, 5-diisocyanatonaphthalene, and dimethylbiphenyl diisocyanate.
Further, in the steps (1), (2) and (3), the rotation speed of the stirring is 900-1000 r/min, and the time is 35-55 min.
Example 2
The difference from the embodiment 1 is that: in the step (1), the temperature of the esterification reaction is 55 ℃; the mass ratio of the dibasic anhydride to the polar solvent to the fatty alcohol is 6:7:2, and other conditions are not changed.
Example 3
The difference from the embodiment 1 is that: in the step (1), the dibasic anhydride is 2,3',4,4' -biphenyltetracarboxylic dianhydride, 1,2,4, 5-pyromellitic dianhydride, 3,3',4,4' -diphenylether tetracarboxylic dianhydride, 2,3,3',4' -diphenylether tetracarboxylic dianhydride, 3,3',4,4' -biphenylsulfone tetracarboxylic dianhydride, 3,3',4,4' -diphenylsulfide tetracarboxylic dianhydride, 3,3',4,4' -triphenylbisether tetracarboxylic dianhydride; the fatty alcohol is ethylene glycol, isopropanol, n-butanol, n-octanol or dodecanol; the polar solvent is 2-chloropyridine, 2, 6-dichloropyridine, N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, propylene glycol methyl ether and dipropylene glycol dimethyl ether; other conditions were unchanged.
Example 4
The difference from the embodiment 1 is that: in the step (2), the mass ratio of the esterification liquid to the binary anhydride, the initiator, the catalyst and the surfactant is 70:75:2:2: 4.5; other conditions were unchanged.
Example 5
The difference from the embodiment 1 is that: in step (2), the foam stabilizer is polysiloxane, tetramethyl silicone oil, AKAKAKAK 8803, DC198, silicone polyether copolymer; the catalyst is diethanolamine, triethanolamine, dimethylethanolamine, dipropylene glycol, triethylene diamine, stannous octoate, dibutyltin diacetate and dibutyltin dilaurate; other conditions were unchanged.
Example 6
The difference from the embodiment 1 is that: in step (3), the two-step curing method is: the first step adopts microwave heating, the temperature of the system is controlled to be 130 ℃, and the time is 35 min; secondly, heating by adopting a vacuum resistance furnace at the temperature of 230 ℃ for 1.7h and under the vacuum degree of 2.8 MPa; other conditions were unchanged.
Example 7
The difference from the embodiment 1 is that: in step (3), the isocyanate is diphenylmethane diisocyanate, polyphenyl polymethylene polyisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, tetramethylxylylene diisocyanate, 4' -diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, 3' -dimethoxy-4, 4' -diphenyl diisocyanate, methylcyclohexane diisocyanate, cyclohexyldimethylene diisocyanate, methyl formate pentamethylene diisocyanate, diphenylmethane-4, 4' -diisocyanate, 1, 5-naphthalene diisocyanate, dimethylbiphenyl diisocyanate, and other conditions are not changed.
Example 8
The difference from the embodiment 1 is that: in the steps (1), (2) and (3), the rotation speed of stirring is 950r/min, the time is 45min, and other conditions are unchanged.
Comparative example 1
The difference from the embodiment 1 is that: in the step (1), the temperature of the esterification reaction is 95 ℃; the mass ratio of the dibasic anhydride to the polar solvent to the fatty alcohol is 16:15: 7; in the step (2), the mass ratio of the esterification liquid to the binary anhydride, the initiator, the catalyst and the surfactant is 20:135:7:9: 1; other conditions were unchanged.
Comparative example 2
The difference from the embodiment 1 is that: in the step (3), during curing, a one-step curing method is adopted for curing, specifically, microwave heating curing is adopted, the temperature of the system is controlled to be 300 ℃, the time is 15min, and other conditions are unchanged.
Comparative example 3
The difference from the embodiment 1 is that: in the step (3), during curing, a one-step curing method is adopted for curing, specifically, a vacuum resistance furnace is adopted for heating and curing, the heating temperature is controlled to be 350 ℃, the time is 5 hours, the pressure is 0.3MPa, and other conditions are unchanged.
Comparative example 4
The preparation of the foam was carried out according to the examples in patent application CN 201710035692.7.
Comparative example 5
The preparation of the foam was carried out according to the examples in patent application CN 201910036701.3.
Comparative example 6
The preparation of the foam was carried out according to the examples in patent application CN 201610339855.6.
Comparative example 7
The preparation of the foam was carried out according to the examples in patent application CN 201110441923.7.
To further illustrate that the present invention can achieve the technical effects, the following experiments were performed:
the polyimide foams were prepared by the methods of examples 1 to 8 and comparative examples 1 to 7, the amounts of the produced polyimide foams were the same for each group, and 1m per production was recorded for each group3The cost required by the polyimide foam material is detected, and the apparent density, the heat conductivity coefficient, the oxygen index, the moisture absorption rate and the imidization conversion rate of the prepared polyimide foam material are detected, wherein the apparent density is detected according to GB/T6343-. The experimental results are shown in table 1 below.
TABLE 1
As can be seen from the experimental data in Table 1, the required cost of the unit cube of the polyimide foam prepared by the method is less than that of the prior art, so that the method can control the production cost and achieve the purpose of industrial production, thereby being more beneficial to the popularization of the polyimide foam material. In addition, it can be seen from table 1 that the polyimide foams prepared herein have low thermal conductivity, low moisture absorption, high oxygen index, and high imide conversion.
In conclusion, after the foaming precursor is prepared by taking the binary anhydride as the substrate, the isocyanate is added for foaming, and the polyimide is prepared by a heating and curing mode of mutually matching a microwave and a vacuum resistance furnace, so that the prepared polyimide foam material has the characteristics of low heat conductivity coefficient, excellent flame retardant property, small moisture absorption rate and the like; and the preparation process is simple, the cost is low, the imidization conversion rate is high, the industrial production is easy, and the popularization and the application are convenient.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (10)
1. A production method of a polyimide foam material is characterized by comprising the following steps: adding a polar solvent and fatty alcohol into a dibasic anhydride serving as a substrate to perform esterification reaction, then adding the dibasic anhydride, an initiator, a catalyst and a surfactant to prepare a foaming precursor, then adding isocyanate to perform foaming, and curing by adopting a two-step curing method after molding and demolding to prepare the polyimide foam material.
2. The method for producing a polyimide foam according to claim 1, comprising the steps of:
(1) preparation of an esterification solution: taking dibasic anhydride as a substrate, adding a polar solvent and fatty alcohol, mixing, uniformly stirring for esterification, and cooling to room temperature to obtain an esterified liquid;
(2) preparing a foaming precursor: adding dibasic anhydride, an initiator, a catalyst and a surfactant into the esterification solution obtained in the step (1), and uniformly stirring to obtain a foaming precursor;
(3) foaming and curing: and (3) adding isocyanate into the foaming precursor in the step (2) in a stirring state, uniformly stirring, quickly transferring into a forming die for forming, demolding, and then heating and curing by adopting a two-step curing method to obtain the polyimide foam material.
3. The method for producing a polyimide foam according to claim 2, wherein: in the step (1), the temperature of the esterification reaction is 40-70 ℃.
4. The method for producing a polyimide foam according to claim 2, wherein: in the step (1), the mass ratio of the dibasic anhydride, the polar solvent and the fatty alcohol is (3-10): 1-3).
5. The method for producing a polyimide foam according to claim 2, wherein: in the step (1), the dibasic anhydride is one or more of 3,3',4,4' -benzophenonetetracarboxylic dianhydride, 2,3,3',4' -benzophenonetetracarboxylic dianhydride, 3,3',4,4' -biphenyltetracarboxylic dianhydride, 2,3',4,4' -biphenyltetracarboxylic dianhydride, 1,2,4, 5-pyromellitic dianhydride, 3,3',4,4' -diphenylethertetracid dianhydride, 2,3,3',4' -diphenylethertetracid dianhydride, 3,3',4,4' -biphenylsulfonetetracarboxylic dianhydride, bisphenol a type diphenylether dianhydride, 3,3',4,4' -diphenylsulfide tetracarboxylic dianhydride, 3,3',4,4' -triphenylbisethertetracarboxylic dianhydride; the fatty alcohol is one or more of methanol, ethanol, ethylene glycol, propanol, isopropanol, n-butanol, n-octanol and dodecanol; the polar solvent is one or more of tetrahydrofuran, 2-chloropyridine, 2, 6-dichloropyridine, dimethyl sulfoxide, N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide, propylene glycol methyl ether and dipropylene glycol dimethyl ether.
6. The method for producing a polyimide foam according to claim 2, wherein: in the step (2), the mass ratio of the esterification liquid to the dibasic anhydride, the initiator, the catalyst and the surfactant is (40-100): 30-100): 1-3): 3-6.
7. The method for producing a polyimide foam according to claim 2, wherein: in the step (2), the foam stabilizer is one or more of polysiloxane, tetramethyl silicone oil, AK series silicone oil, DC series silicone oil, silicone polyether copolymer, organosilicon and silicone; the catalyst is one or more of diethanolamine, triethanolamine, triethylene diamine, dimethylethanolamine, dipropylene glycol, triethylene diamine, organic tin, stannous octoate, dibutyltin diacetate and dibutyltin dilaurate; the initiator is water.
8. The method for producing a polyimide foam according to claim 2, wherein: in step (3), the two-step curing method is: the first step is microwave heating, the temperature of a system is controlled to be 50-200 ℃, and the time is 10-60 min; and in the second step, a vacuum resistance furnace is adopted for heating, the heating temperature is 150-300 ℃, the time is 0.5-4 h, and the vacuum degree is 0.5-5 MPa.
9. The method for producing a polyimide foam according to claim 2, wherein: in the step (3), the isocyanate is phenyl diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, polyphenyl polymethylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, tetramethylxylylene diisocyanate, 4' -diphenylmethane diisocyanate, 1, 5-naphthalene diisocyanate, 3' -dimethoxy-4, 4' -diphenyl diisocyanate, methylcyclohexane diisocyanate, cyclohexyldimethylene diisocyanate, methyl formate pentamethylene diisocyanate, diphenylmethane-4, 4' -diisocyanate, 1, 5-naphthalene diisocyanate, toluene diisocyanate, one or more than one of dimethyl biphenyl diisocyanate.
10. The method for producing a polyimide foam according to claim 2, wherein: in the steps (1), (2) and (3), the stirring speed is 900-1000 r/min, and the time is 35-55 min.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111217999A (en) * | 2020-02-20 | 2020-06-02 | 哈尔滨工程大学 | Environment-friendly preparation method and product of flexible polyimide heat insulation foam |
| CN111690136A (en) * | 2020-07-30 | 2020-09-22 | 贵州航天天马机电科技有限公司 | Microwave-assisted preparation method of polyimide foam material |
| CN112126106A (en) * | 2020-09-28 | 2020-12-25 | 贵州航天天马机电科技有限公司 | High-density hard flame-retardant polyimide foam material and preparation method thereof |
| CN115418020A (en) * | 2022-10-09 | 2022-12-02 | 贵州航天天马机电科技有限公司 | Recycling method of polyimide foam waste |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040249002A1 (en) * | 2003-02-11 | 2004-12-09 | Administrator Of The National Aeronautics And Space Administration | Polyimide foams |
| CN101402743A (en) * | 2008-11-25 | 2009-04-08 | 北京市射线应用研究中心 | Polyimide foam and method of producing the same |
| CN106032433A (en) * | 2015-03-09 | 2016-10-19 | 常州天晟新材料股份有限公司 | Polyimide foamed material and preparation method thereof |
| CN107540839A (en) * | 2016-06-27 | 2018-01-05 | 上海康达化工新材料股份有限公司 | A kind of heat-insulated Polyimide foams of Lightweight acoustical and preparation method thereof |
-
2019
- 2019-09-27 CN CN201910924169.9A patent/CN110655790A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040249002A1 (en) * | 2003-02-11 | 2004-12-09 | Administrator Of The National Aeronautics And Space Administration | Polyimide foams |
| CN101402743A (en) * | 2008-11-25 | 2009-04-08 | 北京市射线应用研究中心 | Polyimide foam and method of producing the same |
| CN106032433A (en) * | 2015-03-09 | 2016-10-19 | 常州天晟新材料股份有限公司 | Polyimide foamed material and preparation method thereof |
| CN107540839A (en) * | 2016-06-27 | 2018-01-05 | 上海康达化工新材料股份有限公司 | A kind of heat-insulated Polyimide foams of Lightweight acoustical and preparation method thereof |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111217999A (en) * | 2020-02-20 | 2020-06-02 | 哈尔滨工程大学 | Environment-friendly preparation method and product of flexible polyimide heat insulation foam |
| CN111217999B (en) * | 2020-02-20 | 2022-07-26 | 哈尔滨工程大学 | Environment-friendly preparation method of flexible polyimide heat insulation foam and product |
| CN111690136A (en) * | 2020-07-30 | 2020-09-22 | 贵州航天天马机电科技有限公司 | Microwave-assisted preparation method of polyimide foam material |
| CN112126106A (en) * | 2020-09-28 | 2020-12-25 | 贵州航天天马机电科技有限公司 | High-density hard flame-retardant polyimide foam material and preparation method thereof |
| CN115418020A (en) * | 2022-10-09 | 2022-12-02 | 贵州航天天马机电科技有限公司 | Recycling method of polyimide foam waste |
| CN115418020B (en) * | 2022-10-09 | 2023-12-05 | 贵州航天天马机电科技有限公司 | Recycling method of polyimide foam waste |
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