CN111154148B - Preparation method of waterborne polyurethane modified starch-based liquid mulching film - Google Patents
Preparation method of waterborne polyurethane modified starch-based liquid mulching film Download PDFInfo
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- C08J5/18—Manufacture of films or sheets
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- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G13/00—Protecting plants
- A01G13/02—Protective coverings for plants; Coverings for the ground; Devices for laying-out or removing coverings
- A01G13/0256—Ground coverings
- A01G13/0268—Mats or sheets, e.g. nets or fabrics
- A01G13/0275—Films
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- C08B31/00—Preparation of derivatives of starch
- C08B31/18—Oxidised starch
- C08B31/185—Derivatives of oxidised starch, e.g. crosslinked oxidised starch
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- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
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- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/42—Polycondensates having carboxylic or carbonic ester groups in the main chain
- C08G18/4236—Polycondensates having carboxylic or carbonic ester groups in the main chain containing only aliphatic groups
- C08G18/4238—Polycondensates having carboxylic or carbonic ester groups in the main chain containing only aliphatic groups derived from dicarboxylic acids and dialcohols
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- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
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- C08G18/00—Polymeric products of isocyanates or isothiocyanates
- C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
- C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
- C08G18/40—High-molecular-weight compounds
- C08G18/48—Polyethers
- C08G18/4854—Polyethers containing oxyalkylene groups having four carbon atoms in the alkylene group
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- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
- A01G13/00—Protecting plants
- A01G2013/004—Liquid mulch
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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
- C08J2303/00—Characterised by the use of starch, amylose or amylopectin or of their derivatives or degradation products
- C08J2303/04—Starch derivatives
- C08J2303/10—Oxidised starch
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- C08J2475/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
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- C08J2475/06—Polyurethanes from polyesters
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- C08J2475/00—Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
- C08J2475/04—Polyurethanes
- C08J2475/08—Polyurethanes from polyethers
Abstract
The invention provides a preparation method of a water-based polyurethane modified starch-based liquid mulching film. According to the invention, the ST is subjected to oxidation treatment by a clean and efficient electric-Fenton technology, the reaction accessibility is improved, the hydration dispersibility of starch molecules and the reaction activity of surface hydroxyl groups are enhanced, an aminosilane coupling agent is utilized for amination modification, and the effective graft copolymerization of Waterborne Polyurethane (WPU) and Aminated Oxidized Starch (AOST) is realized by adopting aqueous emulsion polymerization, so that a novel waterborne polyurethane-starch composite material (AOST-g-WPU) is developed. The AOST-g-WPU is used as an environment-friendly biomass-based liquid mulching film material, and shows excellent soil association force, water absorption, water retention, biocompatibility and degradability.
Description
Technical Field
The invention relates to a preparation method of a water-based polyurethane modified starch-based liquid mulching film, belonging to the field of natural high polymer materials.
Background
With the increasing exhaustion of petroleum resources and the increasing emphasis of governments and the public on the environmental problems caused by white plastic pollution, the polymer materials prepared from petrochemical products cannot meet the requirements of the development of the whole human society, and people aim at green, cheap, renewable and biodegradable natural polymers. Starch (ST) is widely used in agricultural mulching, industrial foam mulching, food packaging, etc. because it is green, inexpensive, renewable and biodegradable. In 1972, Griffin first proposed the use of a screw extruder to prepare biodegradable starch-based polyethylene composites for agricultural mulching. However, experiments have shown that only partial biodegradation of such blended composites can be achieved. Biodegradable starch-based composites have subsequently become a hot spot of research in recent decades. Mainly focuses on the preparation of starch for casting, application and research on food packaging and degradable film materials. In addition, a great deal of research has been conducted on processing techniques of thermoplastic ST (mainly including extrusion, kneading, pressing, injection, etc.), and control of cast molding, biodegradability, and degradation rate has been achieved through research in terms of molecular weight, composition, mixing amount of plasticizer, and the like.
A large number of polar groups (carbamate groups, urea groups and the like) in the Waterborne Polyurethane (WPU) material have good miscibility with natural polymers through the interaction of hydrogen bonds. By blending WPU with natural polymers, the novel material performance is improved, and meanwhile, good biodegradability is kept. In recent years, a series of composite materials prepared by casting and evaporation methods take ST and WPU as raw materials, and research on processing technology of the composite materials is carried out to improve the properties of the two components. But only by means of blending, the difficult complete degradability of the WPU component in the starch-based waterborne polyurethane composite material greatly limits the application range of the WPU component. Therefore, ST is directly introduced into the WPU molecular chain in a crosslinking copolymerization mode, so that the copolymerization material is endowed with biological characteristics such as complete biodegradability, good biocompatibility and the like, is widely applied, and has important theoretical and practical significance.
However, since ST is insoluble in organic solvents such as acetone, toluene and DMF, and when the ST is diluted and dispersed by only organic solvents, the problems exist, such as large amount of used organic solvents, long reaction time, low grafting rate, cross-linking bonding mainly occurs on the surfaces of ST dispersed particles, and polymerization reaction is difficult to be carried out uniformly and thoroughly, so that the reaction reproducibility is poor, the product performance cannot reach theoretical assumption, and the like, namely, the aqueous polyurethane modified starch-based liquid mulching film prepared by the prior art has the problems that the tensile strength of the film is low, and the water absorption rate and the hydrophobicity cannot be ensured simultaneously; has poor soil structure improvement effect and can not be completely degraded.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a preparation method of a waterborne polyurethane modified starch-based liquid mulching film, which realizes the following purposes:
(1) the tensile strength of the adhesive film is improved;
(2) the water absorption is improved, and meanwhile, the paint has certain hydrophobicity;
(3) the degradation performance is good;
(4) has the effect of improving the soil structure.
In order to solve the technical problems, the invention adopts the following technical scheme:
a preparation method of a water-based polyurethane modified starch-based liquid mulching film comprises the steps of preparing oxidized starch dispersion liquid, preparing aminated oxidized starch dispersion liquid, preparing polyurethane prepolymer, chain extension, neutralization and aqueous emulsion polymerization.
The following is a further improvement of the above technical solution:
preparing oxidized starch dispersion liquid, adding a certain amount of water and starch into a reaction kettle, adjusting the pH to 2.9-3.1, heating to 48-52 ℃, adding a quantitative ferrous salt complex solution, and performing constant-current electrolysis with the current density of 10-30A/m2Dropwise adding a certain amount of hydrogen peroxide, adjusting the temperature to 60-70 ℃ after the temperature is stable, keeping the temperature for 60-90min, stopping electrolysis, and cooling.
The mass ratio of the water to the starch is as follows: 2-3:1, preferably 2.3-2.4: 1;
the volume-mass ratio of the ferrous salt complex liquid to the starch is as follows: 1ml is 14-21 g;
the dropping time of the hydrogen peroxide is 0.9-1.1 h;
the mass ratio of the hydrogen peroxide to the starch is as follows: 0.1-0.18:1.
The pH of the oxidized starch dispersion liquid is adjusted to 3.5-4.5, preferably 4.0-4.5; and (3) dropwise adding an aminosilane coupling agent to carry out amination reaction, adjusting the temperature to 45 ℃, keeping the temperature for 60-90min, and adjusting the pH to 6.5-7.0 to prepare the aminated oxidized starch dispersion.
The mass ratio of the amino silane coupling agent to the starch is as follows: 0.05-0.07: 1; the amino silane coupling agent is one of gamma-aminopropyl triethoxysilane or gamma-aminopropyl trimethoxysilane or N-beta (aminoethyl) -gamma-aminopropyl triethoxysilane; the dropping time of the aminosilane coupling agent is 38-42 min.
The preparation method comprises the steps of preparing a polyurethane prepolymer, removing water from quantitative polyether/polyester polyol in vacuum, cooling, adding diisocyanate, reacting at 60-65 ℃ for 30-60 min, heating to 80-85 ℃, keeping the temperature for 60-120 min, and cooling to 58-62 ℃, preferably 60 ℃; the mass ratio of the polyether/polyester polyol to the diisocyanate is as follows: 2.8-5.2: 1;
the mass ratio of the polyether/polyester polyol to the starch is as follows: 1:1.5-2.1.
The molecular weight of the polyether/polyester polyol is 2000-3000;
the isocyanate is one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and dicyclohexylmethane diisocyanate; the polyether/polyester polyol is one of polyoxypropylene ether glycol, polytetrahydrofuran ether glycol, polybutylene adipate glycol and polyethylene adipate glycol, when the isocyanate is isophorone diisocyanate or dicyclohexylmethane diisocyanate, 0.1-0.2% of a catalyst is added, and the catalyst is dibutyltin dilaurate or stannous octoate.
And (3) performing aqueous phase emulsion polymerization, namely adding the aminated oxidized starch dispersion into the aqueous polyurethane prepolymer emulsion under the stirring of 1000-1300r/min, continuing stirring for 10-15 min, reducing the stirring speed to 150-200r/min, and stirring at room temperature for reaction for 60-90min to prepare the aqueous polyurethane modified starch-based liquid mulching material.
The aqueous polyurethane prepolymer emulsion is prepared by chain extending a polyurethane prepolymer until-NCO approaches a theoretical value (detected by a di-n-butylamine method), then performing a neutralization reaction, adding deionized water with the temperature of 4.5-5.5 ℃ and stirring and emulsifying at 1100-1300r/min for 5-10 min to obtain the aqueous polyurethane prepolymer emulsion; the mass ratio of the deionized water to the polyether/polyester polyol is as follows: 2.9-3.5:1.
And (2) chain extension, adding a hydrophilic chain extender into the polyurethane prepolymer, reacting at 58-62 ℃ for 30-60 min, then adding micromolecular dihydric alcohol into the system for chain extension, reacting for 30-60 min, heating to 80-82 ℃, and preserving heat for 2-4 h until NCO approaches to a theoretical value (detected by a di-n-butylamine method).
The micromolecular dihydric alcohol is one of ethylene glycol, propylene glycol, 1, 4-butanediol and diethylene glycol, and the hydrophilic chain extender is one of dimethylolpropionic acid and dimethylolbutyric acid;
the mass ratio of the hydrophilic chain extender to the polyether/polyester polyol is as follows: 1:14.9-20.
The mass ratio of the hydrophilic chain extender to the micromolecular dihydric alcohol is as follows: 1.4-3.3:1.
Neutralizing, namely adding a neutralizing agent, and performing neutralization reaction for 15-30 min;
the neutralizing agent is one of triethylamine and tri-n-butylamine. The proportion of the soft and hard segment components can be adjusted according to the actual requirements of the material.
The mass ratio of the neutralizing agent to the hydrophilic chain extender is as follows: 1:1.2-1.7.
The starch is one of corn starch, potato starch, sweet potato starch and wheat starch, and the content of amylose is 22-26%.
The ferrous salt complex solution is one of ferrous sulfate and sodium citrate, sodium tartrate or sodium oxalate, water is added according to the molar ratio of 1:2, the mixture is stirred and dissolved, the pH value is adjusted to 3.0 by dilute sulfuric acid, and the complex ferrous salt solution, Fe, is obtained2+The concentration was 0.1 mol/L.
The patent technology of the invention utilizes the special molecular structure of Starch (ST) and a large number of active groups (-OH) distributed on the molecular chain of polysaccharide to chemically modify and functionalize the ST. ST is oxidized by a clean and efficient electro-Fenton technology, so that the reaction accessibility is improved, and the reaction activity of the hydroxyl on the surface of the starch is enhanced. Through the amination modification of an aminosilane coupling agent, and the effective graft copolymerization and interpenetrating network of WPU (waterborne polyurethane) and Aminated Oxidized Starch (AOST) are realized by adopting the 'particle design' and aqueous emulsion polymerization, a novel biodegradable green natural high polymer material is prepared, and the preparation method has the following characteristics: (i) the WPU and AOST are grafted and copolymerized by utilizing aqueous emulsion polymerization, so that the problems of brittleness, low elongation and the like of a film formed by single ST are solved; (ii) the composite material shows excellent soil association force, water absorption, water retention, biocompatibility and degradability, and has wide application prospect in modern precision agricultural application such as water conservation, less fertilizer, soil residual film reduction and the like.
Compared with the prior art, the invention has the following technical effects:
1) the invention adopts a green dispersion system, namely, full-aqueous solvent-free aqueous emulsion polymerization to realize chemical crosslinking modification of the aqueous polyurethane to the starch, and meets the current preparation requirements of factories on green and cleanness.
2) The invention utilizes green, cheap and renewable starch as raw material, greatly solves the problems of poor biodegradability, high cost and the like of the conventional waterborne polyurethane, and is more easily accepted by the industry. The market price of the imported liquid mulching film is 1.5-2.0 ten thousand yuan/ton at present, and the cost price of the product is 5000-9000 yuan/ton.
3) The waterborne polyurethane modified starch-based composite liquid mulching film prepared by the invention has good biodegradability, film forming property, hydrophobicity, flexibility, thermal stability, dynamic/static mechanical properties and the like. The tensile strength of an adhesive film of the composite material is 8-15 MPa, the contact angle test is 98-110 degrees, the maximum thermal weight loss temperature is 355.2 ℃, the water absorption rate is 60-80 percent, and the SBF simulated body fluid degradation period is 60-65 days.
4) The product of the invention is applied to the field crop cultivation, and shows good application performances of soil structure improvement, water retention, heat preservation, fertilizer retention and the like. The product disclosed by the invention can form a multi-molecular reticular membrane on the soil surface, and the membrane can seal the pores on the soil surface, prevent the volatilization of water in the soil and does not influence the permeation of water. Meanwhile, the dispersed soil particles can be cemented together to form a soil aggregate structure, and a layer of hydrophobic film is formed on the surface of the soil aggregate structure, so that the effects of improving the soil structure, fixing surface soil and protecting a plough layer are achieved. Meanwhile, the good biodegradability effectively solves the problem of soil residual membrane, and has wide market demand.
5) After the product is applied, the seedling emergence period can be shortened, is about 5-6 days earlier than that of bare land, and the seedling emergence rate is improved, is about 10% higher than that of the bare land respectively, and is obviously better than that of the bare land in growth vigor, dark green degree and leaf width.
Drawings
FIG. 1 is a flow chart of the process for preparing the product of the present invention;
FIG. 2 is a diagram showing the comparison of emergence and growth of corn seedlings with bare soil and sprayed with the liquid mulching film of the present invention after corn is sowed for 1 week;
FIG. 3 is a diagram showing the comparison of emergence and growth of corn seedlings with bare soil and sprayed with the liquid mulching film of the present invention after corn seeding for 5 weeks;
in fig. 2 and 3, the left border is bare soil, and the right border is sprayed with the liquid mulching film of the invention;
FIG. 4 is an SEM image of the soil association morphology before and after spraying of a liquid mulch film;
FIG. 5 is an SEM image of the soil association morphology after spraying of the liquid mulching film.
Detailed Description
Example 1
A preparation method of a water-based polyurethane modified starch-based liquid mulching film comprises the following steps:
(1) preparation of oxidized starch Dispersion
490 g of water and 210 g of corn starch are added into a 1L five-neck flask, the rotation speed is 150 r/min, the mixture is uniformly stirred, dilute sulfuric acid is added to adjust the pH value to 3.0, the temperature is increased to 50 ℃, 15 mL0.1 mol/L ferrous salt complex liquid (the molar ratio of ferrous sulfate to sodium tartrate is 1: 2) is added, an electrode is inserted, a graphite electrode is an anode, a titanium electrode is a cathode, a calomel electrode is a reference, an electrochemical analysis system is switched on to carry out constant-current electrolysis, and the current density is 10-30A/m2. Dropwise adding 31.5 g of hydrogen peroxide, dropping for about 1 hour, rapidly increasing the temperature in the period, adjusting the temperature to 60-70 ℃ after the temperature is stable, keeping the temperature for 90min, closing an electrochemical analysis system, taking out an electrode, and cooling for later use.
(2) Preparation of aminated oxidized starch Dispersion
And (2) adjusting the pH value of the oxidized starch dispersion liquid obtained in the step (1) to 4.0-4.5, dropwise adding 12 g N-beta (aminoethyl) -gamma-aminopropyltrimethoxysilane to carry out an amination reaction for about 40 min, adjusting the temperature to 45 ℃, keeping the temperature for 90min, and adjusting the pH value of a sodium hydroxide solution to 6.5-7.0 to obtain an aminated oxidized starch dispersion liquid for later use.
(3) Preparation of polyurethane prepolymer
Weighing 118 g of polytetrahydrofuran ether glycol (molecular weight 2000), dehydrating in vacuum at 110 ℃ for 1-2 h, cooling to 60 ℃, adding 26.2 g of isophorone diisocyanate and 1 drop of dibutyltin dilaurate catalyst, reacting for 1h, heating to 84 ℃, preserving heat for 1h to obtain a polyurethane prepolymer, and cooling to 60 ℃;
one drop is about 0.05 ml.
(4) Chain extension
And (3) adding 6.5 g of dimethylolpropionic acid into the prepolymer for chain extension, reacting at 60 ℃ for 1h, adding 2 g of ethylene glycol into the system for chain extension, reacting at 60 ℃ for 1h, keeping the temperature for 1h, heating to 80 ℃, and reacting for 2-3 h.
(5) Neutralization
And cooling to room temperature, adding 4.3 g of triethylamine for neutralization, and reacting for 15-20 min. And after the temperature is reduced to room temperature, adding 350 g of deionized water with the temperature of 5 ℃, and stirring at 1200 r/min for 5 min to obtain the water-based polyether type polyurethane prepolymer emulsion.
(6) Preparation of composite liquid mulching material
And (3) adding the aminated oxidized starch dispersion liquid obtained in the step (2) into the solution obtained in the step (5) under the action of high-speed shearing at 1000 r/min, continuously reacting with-NCO in the polyurethane aqueous prepolymer emulsion in a water phase (reacting at room temperature), continuously stirring for 10 min, reducing the stirring speed to 150-200r/min, reacting for 90min, and discharging from the kettle to obtain the aqueous polyether polyurethane modified starch-based composite liquid mulching material.
Example 2
A preparation method of a water-based polyurethane modified starch-based liquid mulching film comprises the following steps:
(1) preparation of oxidized starch Dispersion
490 g of water and 210 g of potato starch are added into a 1L five-neck flask, the rotation speed is 150 r/min, the mixture is uniformly stirred, dilute sulfuric acid is added to adjust the pH value to 3.0, the temperature is increased to 50 ℃, 10 mL0.1 mol/L ferrous salt complex liquid (the molar ratio of ferrous sulfate to sodium citrate is 1: 2) is added, an electrode is inserted, a graphite electrode is an anode, a titanium electrode is a cathode, a calomel electrode is a reference, an electrochemical analysis system is switched on to carry out constant-current electrolysis, and the current density is 10-30A/m2. Dropping 21g of hydrogen peroxide, dropping for about 1 hour, rapidly increasing the temperature during the dropping, and adjusting the temperature after the temperature is stableAnd (3) keeping the temperature for 90min when the temperature reaches 60-70 ℃, closing the electrochemical analysis system, taking out the electrode, and cooling for later use.
(2) Preparation of aminated oxidized starch Dispersion
And (2) adjusting the pH value of the oxidized starch dispersion liquid obtained in the step (1) to 3.5-4.5, dropwise adding 11 g of gamma-aminopropyltriethoxysilane for amination reaction, dropwise adding the mixture for about 40 min, adjusting the temperature to 45 ℃, keeping the temperature for 90min, and adjusting the pH value of a sodium hydroxide solution to 6.5-7.0 to obtain an aminated oxidized starch dispersion liquid for later use.
(3) Preparation of polyurethane prepolymer
Weighing 26.1 g of toluene diisocyanate and 100 g of vacuum dehydrated polyoxypropylene ether glycol (molecular weight 2000), reacting at 65 ℃ for 1h, heating to 82 ℃, preserving heat for 1-2 h to obtain a polyether polyurethane prepolymer, and cooling to 60 ℃;
toluene diisocyanate was added simultaneously with the polyoxypropylene ether diol.
(4) Chain extension
And (3) adding 6.7 g of dimethylolbutyric acid into the prepolymer for chain extension, reacting for 1h at 60 ℃, adding 2.5 g of 1, 4-butanediol into the system for chain extension, keeping the temperature at 60 ℃ for 1h, heating to 80 ℃, and reacting for 2-3 h.
(5) Neutralization
And cooling to room temperature, and adding 5.5 g of tri-n-butylamine for neutralization, wherein the reaction time is 15-20 min. After the temperature is cooled to room temperature, 320g of deionized water with the temperature of 5 ℃ is added, and the mixture is stirred for 5 min at the speed of 1200 r/min, so that the water-based polyether type polyurethane prepolymer emulsion is obtained.
(6) Preparation of composite liquid mulching material
And (3) adding the aminated oxidized starch dispersion liquid obtained in the step (2) into the solution obtained in the step (5) under the action of high-speed shearing at 1000 r/min, continuously reacting with-NCO in the polyurethane aqueous prepolymer emulsion in the water phase, continuously stirring for 10 min, reducing the stirring speed to 150-200r/min, reacting for 60min, and discharging from the kettle to obtain the aqueous polyether polyurethane modified starch-based liquid mulching film composite material.
Example 3
A preparation method of a water-based polyurethane modified starch-based liquid mulching film comprises the following steps:
(1) preparation of oxidized starch Dispersion
490 g of water and 210 g of sweet potato starch are added into a 1L five-neck flask, the mixture is stirred uniformly at the rotating speed of 150 r/min, dilute sulfuric acid is added to adjust the pH value to 3.0, the temperature is raised to 50 ℃, 12 mL0.1 mol/L ferrous salt complex liquid (the molar ratio of ferrous sulfate to sodium oxalate is 1: 2) is added, an electrode is inserted, a graphite electrode is an anode, a titanium electrode is a cathode, a calomel electrode is a reference, an electrochemical analysis system is switched on to carry out constant-current electrolysis, and the current density is 10-30A/m2. Dropwise adding 25.2 g of hydrogen peroxide, dropping for about 1 hour, rapidly increasing the temperature in the period, adjusting the temperature to 60-70 ℃ after the temperature is stable, keeping the temperature for 90min, closing an electrochemical analysis system, taking out an electrode, and cooling for later use.
(2) Preparation of aminated oxidized starch Dispersion
And (2) adjusting the pH value of the oxidized starch dispersion liquid obtained in the step (1) to 3.5-4.5, dropwise adding 13 g N-beta (aminoethyl) -gamma-aminopropyltriethoxysilane for amination reaction, completing dropwise adding for about 40 min, adjusting the temperature to 45 ℃, keeping the temperature for 90min, and adjusting the pH value of a sodium hydroxide solution to 6.5-7.0 to obtain an aminated oxidized starch dispersion liquid for later use.
(3) Preparation of polyurethane prepolymer
Weighing 100 g of polybutylene adipate glycol (molecular weight 2000), dehydrating in vacuum at 110 ℃ for 1-2 h, cooling to 60 ℃, adding 35 g of dicyclohexylmethane diisocyanate and 2 drops (one drop about 0.05 mL) of stannous octoate catalyst, reacting for 1h, heating to 84 ℃, keeping the temperature for 1h to obtain a prepolymer, and cooling to 60 ℃.
(4) Chain extension
And (3) adding 5.5 g of dimethylolpropionic acid into the prepolymer for chain extension, reacting at 60 ℃ for 1h, adding 3.7 g of diethylene glycol into the system for chain extension, keeping the temperature at 60 ℃ for 1h, heating to 82 ℃, and reacting for 2-3 h.
(5) Neutralization
And cooling to room temperature, adding 4 g of triethylamine for neutralization, and reacting for 15-20 min. And (3) after the temperature is reduced to room temperature, adding 340 g of deionized water with the temperature of 5 ℃, stirring and emulsifying at the speed of 1200 r/min for 5 min to obtain the water-based polyester type polyurethane prepolymer.
(6) Preparation of composite liquid mulching material
And (3) adding the aminated oxidized starch dispersion liquid obtained in the step (2) into the solution obtained in the step (5) under the high-speed shearing action of 1200 r/min, continuously reacting with-NCO in the polyurethane aqueous prepolymer emulsion in the water phase, continuously stirring for 10 min, reducing the stirring speed to 150-200r/min, reacting for 90min, and discharging from a kettle to obtain the aqueous polyester type polyurethane modified starch-based liquid mulching film composite material.
Example 4
A preparation method of a water-based polyurethane modified starch-based liquid mulching film comprises the following steps:
(1) preparation of oxidized starch Dispersion
490 g of water and 210 g of wheat starch are added into a 1L five-neck flask, the rotation speed is 150 r/min, the mixture is uniformly stirred, dilute sulfuric acid is added to adjust the pH value to 3.0, the temperature is increased to 50 ℃, 10 mL0.1 mol/L ferrous salt complex liquid (the molar ratio of ferrous sulfate to sodium citrate is 1: 2) is added, an electrode is inserted, a graphite electrode is an anode, a titanium electrode is a cathode, a calomel electrode is a reference, an electrochemical analysis system is switched on to carry out constant-current electrolysis, and the current density is 10-30A/m2. Dropwise adding 27.3 g of hydrogen peroxide, dropping for about 1 hour, rapidly increasing the temperature in the period, adjusting the temperature to 60-70 ℃ after the temperature is stable, preserving the temperature for 60min, closing an electrochemical analysis system, taking out an electrode, and cooling for later use.
(2) Preparation of aminated oxidized starch Dispersion
And (2) adjusting the pH value of the oxidized starch dispersion liquid obtained in the step (1) to 3.5-4.5, dropwise adding 11 g of gamma-aminopropyltrimethoxysilane for amination reaction, dropwise adding the gamma-aminopropyltrimethoxysilane for about 40 min, adjusting the temperature to 45 ℃, keeping the temperature for 90min, and adjusting the pH value of a sodium hydroxide solution to 6.5-7.0 to obtain an aminated oxidized starch dispersion liquid for later use.
(3) Preparation of polyurethane prepolymer
Weighing 100 g of polyethylene glycol adipate glycol (molecular weight 2000), dehydrating in vacuum at 110 ℃ for 1-2 h, cooling to 60 ℃, adding 35 g of diphenylmethane diisocyanate, reacting for 1h, heating to 84 ℃, preserving heat for 1h to obtain a prepolymer, and cooling to 60 ℃.
(4) Chain extension
And (3) adding 6.0 g of dimethylolbutyric acid into the prepolymer for chain extension, reacting for 1h at 60 ℃, adding 3 g of propylene glycol into the system for chain extension, keeping the temperature at 60 ℃ for 1h, heating to 80 ℃, and reacting for 3-4 h.
(5) Neutralization
And cooling to room temperature, adding 3.5 g of triethylamine for neutralization, and reacting for 15-20 min. After the temperature is reduced to room temperature, 335 g of deionized water with the temperature of 5 ℃ is added, and stirring and emulsification are carried out for 5 min at the speed of 1200 r/min, so as to obtain the water-based polyester type polyurethane prepolymer.
(6) Preparation of composite liquid mulching material
And (3) adding the aminated oxidized starch dispersion liquid obtained in the step (2) into the solution obtained in the step (5) under the high-speed shearing action of 1200 r/min, continuously reacting with-NCO in the polyurethane aqueous prepolymer emulsion in the water phase, continuously stirring for 10 min, reducing the stirring speed to 150-200r/min, reacting for 60min, and discharging from a kettle to obtain the aqueous polyester type polyurethane modified starch-based liquid mulching film composite material.
Example 5
A preparation method of a water-based polyurethane modified starch-based liquid mulching film comprises the following steps:
(1) preparation of oxidized starch Dispersion
490 g of water and 210 g of corn starch are added into a 1L five-neck flask, the rotation speed is 150 r/min, the mixture is uniformly stirred, dilute sulfuric acid is added to adjust the pH value to 3.0, the temperature is increased to 50 ℃, 15 mL0.1 mol/L ferrous salt complex liquid (the molar ratio of ferrous sulfate to sodium tartrate is 1: 2) is added, an electrode is inserted, a graphite electrode is an anode, a titanium electrode is a cathode, a calomel electrode is a reference, an electrochemical analysis system is switched on to carry out constant-current electrolysis, and the current density is 10-30A/m2. Dropwise adding 37.8 g of hydrogen peroxide, dropping for about 1 hour, rapidly increasing the temperature in the period, adjusting the temperature to 60-70 ℃ after the temperature is stable, keeping the temperature for 90min, closing an electrochemical analysis system, taking out an electrode, and cooling for later use.
(2) Preparation of aminated oxidized starch Dispersion
And (2) adjusting the pH value of the oxidized starch dispersion liquid obtained in the step (1) to 3.5-4.5, dropwise adding 14 g of gamma-aminopropyltriethoxysilane for amination reaction, dropwise adding the mixture for about 40 min, adjusting the temperature to 45 ℃, keeping the temperature for 90min, and adjusting the pH value of a sodium hydroxide solution to 6.5-7.0 to obtain an aminated oxidized starch dispersion liquid for later use.
(3) Preparation of polyurethane prepolymer
Weighing 27 g of toluene diisocyanate and 140 g of vacuum dehydrated polyoxypropylene ether glycol (molecular weight is 3000), reacting for 1h at 65 ℃, heating to 82 ℃, preserving heat for 1-2 h to obtain a prepolymer, and cooling to 60 ℃.
(4) Chain extension
And (3) adding 7 g of dimethylolpropionic acid into the prepolymer for chain extension, reacting at 60 ℃ for 1h, adding 5 g of diethylene glycol into the system for chain extension, keeping the temperature at 60 ℃ for 1h, heating to 82 ℃ and reacting for 2-3 h.
(5) Neutralization
Cooling to room temperature, adding 5 g of triethylamine for neutralization, preserving heat for 30 min, cooling to room temperature, adding 420 g of 5 ℃ deionized water, and stirring at 1200 r/min for 5 min to obtain the water-based polyether type polyurethane prepolymer emulsion.
(6) Preparation of composite liquid mulching material
And (3) adding the aminated oxidized starch dispersion liquid obtained in the step (2) into the solution obtained in the step (5) under the high-speed shearing action of 1200 r/min, continuously reacting with-NCO in the polyurethane aqueous prepolymer emulsion in the water phase, continuously stirring for 10 min, reducing the stirring speed to 150-200r/min, reacting for 60min, and discharging from the kettle to obtain the aqueous polyether polyurethane modified starch-based liquid mulching film composite material.
The product of the invention can form a multi-molecular reticular membrane on the soil surface, and the membrane can seal the pores on the soil surface, prevent the volatilization of water in the soil and does not influence the permeation of water. Meanwhile, the dispersed soil particles can be cemented together to form a soil aggregate structure.
The following examples are used to illustrate the use of the product for field crop cultivation.
Example 6
20 kg of the product prepared by the invention and 80 kg of water are mixed and stirred uniformly. The fertilizer is sprayed on the ground by a high-pressure sprayer to form a film on the day after sowing according to the dosage of 25-30 kg per mu. Through data statistics, the liquid mulching film has a promoting effect on the growth and development of the corn, the emergence period is about 5-6 days earlier than that of the bare land, the emergence rate is about 10% higher than that of the bare land, and the growth vigor, the dark green degree and the leaf width are obviously better than those of the bare land.
Example 7
15 kg of the product prepared according to the invention and 75 kg of water are mixed and stirred uniformly. The fertilizer is sprayed on the ground by a high-pressure sprayer to form a film on the day after sowing according to the dosage of 25-30 kg per mu. And (3) periodically detecting the water content and the temperature of the soil at different depths covered by the liquid film surface by adopting a field micro-area test mode. Taking 7 d after sowing as an example, in the test field sprayed with the liquid mulching film, the soil layer humidity of 5 cm, 10 cm, 15 cm and 20 cm is respectively 14 percent higher, 10 percent higher, 5 percent higher and 3 percent higher than that of the bare land, and the soil layer temperature is respectively 6 ℃, 5 ℃,4 ℃ and 3 ℃ higher than that of the bare land.
Meanwhile, the product of the invention can effectively promote the soil to form granules, and a layer of hydrophobic film is formed on the surface, thereby playing the roles of improving the soil structure, fixing the surface soil and protecting the plough layer.
Claims (3)
1. A preparation method of a water-based polyurethane modified starch-based liquid mulching film is characterized by comprising the following steps: the preparation method comprises the steps of preparing oxidized starch dispersion liquid, preparing aminated oxidized starch dispersion liquid, preparing polyurethane prepolymer and polymerizing water-phase emulsion;
preparing oxidized starch dispersion liquid, adding a certain amount of water and starch into a reaction kettle, adjusting the pH to 2.9-3.1, heating to 48-52 ℃, adding a certain amount of ferrous salt complex liquid, and performing constant current electrolysis with the current density of 10-30A/m2Dropwise adding a certain amount of hydrogen peroxide, adjusting the temperature to 60-70 ℃ after the temperature is stable, preserving the temperature for 60-90min, stopping electrolysis, and cooling;
the mass ratio of the water to the starch is as follows: 2-3: 1; the volume-mass ratio of the ferrous salt complex liquid to the starch is as follows: 1ml is 14-21 g; the mass ratio of the hydrogen peroxide to the starch is as follows: 0.1-0.18: 1;
preparing an aminated oxidized starch dispersion, and adjusting the pH of the oxidized starch dispersion to 3.5-4.5; dropping aminosilane coupling agent for amination reaction, adjusting the temperature to 45 ℃, keeping the temperature for 60-90min, and adjusting the pH value to 6.5-7.0 to prepare aminated oxidized starch dispersion liquid;
the mass ratio of the amino silane coupling agent to the starch is as follows: 0.05-0.07: 1; the amino silane coupling agent is one of gamma-aminopropyl triethoxysilane or gamma-aminopropyl trimethoxysilane or N-beta (aminoethyl) -gamma-aminopropyl triethoxysilane; the dropping time of the aminosilane coupling agent is 38-42 min;
preparing a polyurethane prepolymer, namely removing water from quantitative polyether polyol/polyester polyol in vacuum, cooling, adding diisocyanate, reacting at the temperature of 60-65 ℃ for 30-60 min, heating to 80-85 ℃, preserving heat for 60-120 min, and cooling to 58-62 ℃; the mass ratio of the polyether polyol/polyester polyol to the diisocyanate is as follows: 2.8-5.2: 1;
the mass ratio of the polyether polyol/polyester polyol to the starch is as follows: 1: 1.5-2.1;
a step of water-based polyurethane prepolymer emulsion, which is to perform chain extension on the polyurethane prepolymer, then perform neutralization reaction, add deionized water with the temperature of 4.5-5.5 ℃ and stir and emulsify for 5-10 min at the temperature of 1100-;
the mass ratio of the deionized water to the polyether polyol/polyester polyol is as follows: 2.9-3.5: 1;
and (3) performing aqueous phase emulsion polymerization, namely adding the aminated oxidized starch dispersion into the aqueous polyurethane prepolymer emulsion under the stirring of 1000-1300r/min, continuing stirring for 10-15 min, reducing the stirring speed to 150-200r/min, and stirring at room temperature for reaction for 60-90min to prepare the aqueous polyurethane modified starch-based liquid mulching material.
2. The preparation method of the aqueous polyurethane modified starch-based liquid mulching film according to claim 1, wherein the method comprises the following steps: and (2) chain extension, namely adding a hydrophilic chain extender, reacting at 58-62 ℃ for 30-60 min, then adding micromolecular dihydric alcohol into the system for chain extension, reacting for 30-60 min, heating to 80-82 ℃, and preserving heat for 2-4 h.
3. The method for preparing the aqueous polyurethane modified starch-based liquid mulching film according to claim 1, wherein the isocyanate is one of toluene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate and dicyclohexylmethane diisocyanate;
the polyether polyol/polyester polyol is one of polyoxypropylene ether glycol, polytetrahydrofuran ether glycol, polybutylene adipate glycol and polyethylene adipate glycol;
when the isocyanate is isophorone diisocyanate or dicyclohexylmethane diisocyanate, 0.1-0.2% of catalyst is added, and the catalyst is dibutyltin dilaurate or stannous octoate.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1935878A (en) * | 2006-10-20 | 2007-03-28 | 中国科学院长春应用化学研究所 | Multifunctional degradable liquid-state mulch film and its preparing method |
| CN101161718A (en) * | 2007-11-27 | 2008-04-16 | 中国科学院长春应用化学研究所 | Biological degradation liquid film and preparation method |
| CN101735420A (en) * | 2008-11-20 | 2010-06-16 | 中国农业科学院农业环境与可持续发展研究所 | Preparation method and application method of biomass liquid agricultural membrane material |
| CN102585485A (en) * | 2012-01-06 | 2012-07-18 | 华南理工大学 | Starch/thermoplastic polyurethane (TPU) composite material with high mechanical property and preparation method thereof |
| CN106700564A (en) * | 2015-08-12 | 2017-05-24 | 四川震鸿科技有限公司 | Multifunctional biodegradable environment-friendly liquid mulching film |
| CN110229342A (en) * | 2019-05-20 | 2019-09-13 | 齐鲁工业大学 | A method of the composite liquefied mulch of collagen-base is prepared by tanning waste |
| CN110563914A (en) * | 2019-09-06 | 2019-12-13 | 四川大学 | Preparation method of biomass high-capacity liquid base membrane |
-
2020
- 2020-02-20 CN CN202010103678.8A patent/CN111154148B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1935878A (en) * | 2006-10-20 | 2007-03-28 | 中国科学院长春应用化学研究所 | Multifunctional degradable liquid-state mulch film and its preparing method |
| CN101161718A (en) * | 2007-11-27 | 2008-04-16 | 中国科学院长春应用化学研究所 | Biological degradation liquid film and preparation method |
| CN101735420A (en) * | 2008-11-20 | 2010-06-16 | 中国农业科学院农业环境与可持续发展研究所 | Preparation method and application method of biomass liquid agricultural membrane material |
| CN102585485A (en) * | 2012-01-06 | 2012-07-18 | 华南理工大学 | Starch/thermoplastic polyurethane (TPU) composite material with high mechanical property and preparation method thereof |
| CN106700564A (en) * | 2015-08-12 | 2017-05-24 | 四川震鸿科技有限公司 | Multifunctional biodegradable environment-friendly liquid mulching film |
| CN110229342A (en) * | 2019-05-20 | 2019-09-13 | 齐鲁工业大学 | A method of the composite liquefied mulch of collagen-base is prepared by tanning waste |
| CN110563914A (en) * | 2019-09-06 | 2019-12-13 | 四川大学 | Preparation method of biomass high-capacity liquid base membrane |
Non-Patent Citations (6)
| Title |
|---|
| "Development of blend films from soy meal protein and crude glycerol-based waterborne polyurethane";Xinjie Tong等;《Industrial Crops and Products》;20150115;第67卷;第11-17页 * |
| "Investigations on oxidised starch based waterborne polyurethane nanocomposites";D. Y. Yang等;《Plastics, Rubber and Composites》;20131112;第41卷(第10期);第425-429页 * |
| "The oxidation of potato starch by Electro-Fenton system in the presence of Fe(II) ions";Xugang Dang等;《International Journal of Biological Macromolecules》;20181002;第121卷;第113-119页 * |
| "氧化玉米淀粉/明胶复合材料的制备及吸水性能研究";党旭岗等;《中国皮革》;20160503;第45卷(第5期);第36-38页和第48页 * |
| "水性聚氨酯对淀粉浆料的改性作用";吕福菊等;《棉纺织技术》;20120710;第40卷(第7期);第412-415页 * |
| "液态地膜与制革废弃物资源化";党旭岗等;《皮革科学与工程》;20151228;第25卷(第6期);第23-27页和第33页 * |
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