阅读说明：本技术 一种基于聚乙烯醇的农药缓释膜及其制备方法 (Pesticide slow-release film based on polyvinyl alcohol and preparation method thereof ) 是由 倪益华 倪忠进 顾程松 窦宝顺 于 2020-07-17 设计创作，主要内容包括：本发明提供了一种基于聚乙烯醇的农药缓释膜及其制备方法,属于农业生产技术领域。本发明的配方包括如下组分：10～15份混合聚乙烯醇料、14～20份载体基料、1～3份农药阿维菌素、0.5～1.8份生物质炭、1～3份十二烷基甜菜碱、0.1～0.4份甲醛、2～5份甘油、0.2～0.5份助剂、110～130份水,其中的混合聚乙烯醇料,即较低分子量的聚乙烯醇和较高分子量聚乙烯醇的混合；载体基料的制备：取偏铝酸钠溶液、碳酸氢钠于密封容器混合,调节pH,于40～60℃,通入二氧化碳气体,控制二氧化碳气体的压力,在通气的同时震荡液体,老化、分离洗涤,干燥,即得载体基料。本发明能够通过膜自身不同程度的降解逐层释放农药,起到缓释的效果。(The invention provides a pesticide slow-release film based on polyvinyl alcohol and a preparation method thereof, belonging to the technical field of agricultural production. The formula of the invention comprises the following components: 10-15 parts of a mixed polyvinyl alcohol material, 14-20 parts of a carrier base material, 1-3 parts of pesticide abamectin, 0.5-1.8 parts of biomass charcoal, 1-3 parts of dodecyl betaine, 0.1-0.4 part of formaldehyde, 2-5 parts of glycerol, 0.2-0.5 part of an auxiliary agent and 110-130 parts of water, wherein the mixed polyvinyl alcohol material is a mixture of polyvinyl alcohol with a lower molecular weight and polyvinyl alcohol with a higher molecular weight; preparation of carrier base material: mixing sodium metaaluminate solution and sodium bicarbonate in a sealed container, adjusting the pH value, introducing carbon dioxide gas at 40-60 ℃, controlling the pressure of the carbon dioxide gas, vibrating the liquid while introducing the gas, aging, separating, washing and drying to obtain the carrier base material. The invention can release the pesticide layer by layer through the degradation of the film per se in different degrees, thereby achieving the effect of slow release.)

1. A pesticide slow-release film based on polyvinyl alcohol is characterized by comprising the following components in parts by weight:

10-15 parts of mixed polyvinyl alcohol material, 14-20 parts of carrier base material, 1-3 parts of pesticide abamectin, 0.5-1.8 parts of biomass charcoal, 1-3 parts of dodecyl betaine, 0.1-0.4 part of formaldehyde, 2-5 parts of glycerol, 0.2-0.5 part of auxiliary agent and 110-130 parts of water.

2. The polyvinyl alcohol-based pesticide sustained-release film according to claim 1, wherein the mixed polyvinyl alcohol material: according to the mass ratio of 5-8: 1-3: 0.01 mixing polyvinyl alcohol with the molecular weight of 1000-2000, polyvinyl alcohol with the molecular weight of 5000-8000 and a modifier.

3. The polyvinyl alcohol-based pesticide sustained-release film according to claim 2, wherein the modifier: according to the mass ratio of 3-7: 0.01 taking silane coupling agent KH-550 and nano titanium dioxide.

4. The polyvinyl alcohol-based pesticide sustained-release film according to claim 1, wherein the auxiliary agent: according to the mass ratio of 4-8: 1, mixing starch and dextrin to obtain the auxiliary agent.

5. The polyvinyl alcohol-based pesticide sustained-release film according to claim 1, wherein the preparation of the carrier base material comprises: according to the mass ratio of 20-30: and 3, mixing 20-30% by mass of sodium metaaluminate solution and sodium bicarbonate in a sealed container, adjusting the pH, introducing carbon dioxide gas at 40-60 ℃, controlling the pressure of the carbon dioxide gas, vibrating the liquid while introducing the gas, aging, separating, washing and drying to obtain the carrier base material.

6. The pesticide slow-release film based on polyvinyl alcohol according to claim 5, wherein the aging temperature in the aging step is 40-60 ℃, and the aging time is 60-90 min.

7. The polyvinyl alcohol-based pesticide slow-release film according to claim 5, wherein in the separation and washing step, the washing temperature is 30-50 ℃, and the washing times are 5-10; the pH value of the final washing wastewater is 6.8-7.3; the temperature in the drying step is 85-100 ℃, and the drying time is 4-8 h.

8. A preparation method of the polyvinyl alcohol-based pesticide sustained-release film according to any one of claims 1 to 7, characterized by comprising the following steps:

(1) taking the following components in parts by weight: 10-15 parts of mixed polyvinyl alcohol material, 14-20 parts of carrier base material, 1-3 parts of pesticide avermectin, 0.5-1.8 parts of biomass charcoal, 1-3 parts of dodecyl betaine, 0.1-0.4 part of formaldehyde, 2-5 parts of glycerol, 0.2-0.5 part of auxiliary agent and 110-130 parts of water;

(2) heating water to 35-45 ℃ for heat preservation, adding a mixed polyvinyl alcohol material, a carrier base material and water for mixing and stirring, heating to 70-85 ℃, sealing and stirring, accelerating stirring, cooling, adding dodecyl betaine, stirring at room temperature to obtain a mixed solution, adding pesticide avermectin, biomass charcoal, formaldehyde and an auxiliary agent, stirring at normal temperature until the mixed solution is dissolved to obtain a mixed solution, carrying out heat preservation and stirring at 50-65 ℃, adding glycerol for mixing and stirring, carrying out vacuum degassing, uniformly spreading a drainage fluid, drying to obtain a membrane A, and carrying out hot-pressing lamination with a membrane B with the same size to obtain the pesticide slow-release membrane based on polyvinyl alcohol.

9. The method for preparing a polyvinyl alcohol-based pesticide sustained-release film according to claim 8, wherein the pressure of the vacuum degassing is 0.05 to 0.08 MPa; controlling the temperature and drying at 28-35 ℃; the thickness of the dried film is 0.16-0.45 mm.

10. The method for preparing a polyvinyl alcohol-based pesticide sustained-release film according to claim 8, wherein the film B is prepared substantially in accordance with the film A except that a modifier is not added to the mixed polyvinyl alcohol material.

Technical Field

The invention relates to the technical field of agricultural production, in particular to a pesticide slow-release film based on polyvinyl alcohol and a preparation method thereof.

Background

Agriculture belongs to the first industry and is a basic product for supporting national economic construction and development. In agricultural production, various types of pesticides are used in order to guarantee and promote the growth of plants and crops. Because a user can not effectively control the prevention and control of diseases, pests and weeds in a proper period and repeatedly use the pesticide, soil hardening is caused, the pesticide resistance of germs and pests to the pesticide is enhanced, the atmosphere and water environment are polluted, the human health is harmed, and meanwhile, the cost investment is increased. Traditional chemical pesticides can effectively control weeds and pests, but potential runoff and eluviation of toxic compounds in soil can cause resource waste and environmental pollution, a large amount of pests are remained in crops, and human health is endangered, so that the application of the chemical pesticides is limited. Therefore, the use of techniques for reducing the toxicity of pesticides and improving the pesticides has been receiving increasing attention.

Controlled release systems for pesticides are gaining increasing favor from researchers due to their economic and ecological advantages. The pesticide controlled release system can effectively control the release of active ingredients, prolong the pesticide effect period, reduce the pesticide dosage and reduce the harm to a pesticide applicator. The application of the controlled release system can reduce the pollution of the pesticide to water and soil, reduce the residue of the pesticide in grains, melons, fruits and vegetables and reduce the harm of the pesticide to the environment. Therefore, the combination of the plant pesticide and the controlled release material not only can effectively improve the utilization rate of the pesticide, but also plays a positive role in agricultural production and ecological environment protection.

Polyvinyl alcohol (PVA) is a biodegradable polymer having many useful properties such as excellent chemical resistance, optical and physical properties, good film forming ability, water solubility and excellent biocompatibility. Starch (ST) is a renewable natural polymer material, is low in price, biodegradable and widely applicable. At present, the research of preparing the sustained-release membrane by combining PVA and ST is less in China.

The fundamental trends in modern world agricultural development are high commercialization, capitalization, scaling, specialization, regionalization, factorization, knowledgeability, socialization, and internationalization. The high-efficiency low-toxicity pesticide is not twistable to replace the high-toxicity pesticide. The research on how to stabilize the pesticide components, control the release speed of the effective components and prolong the plant protection period of the pesticide components, particularly the slow-release film, is a technical problem worthy of research.

Disclosure of Invention

The invention aims to provide a pesticide slow-release film based on polyvinyl alcohol and a preparation method thereof, which can release pesticides layer by layer through degradation of the film per se in different degrees and achieve a slow-release effect.

In order to achieve the purpose, the invention adopts the following technical scheme:

a pesticide slow-release film based on polyvinyl alcohol comprises the following components in parts by weight:

10-15 parts of mixed polyvinyl alcohol material, 14-20 parts of carrier base material, 1-3 parts of pesticide abamectin, 0.5-1.8 parts of biomass charcoal, 1-3 parts of dodecyl betaine, 0.1-0.4 part of formaldehyde, 2-5 parts of glycerol, 0.2-0.5 part of auxiliary agent and 110-130 parts of water.

Further, the mixed polyvinyl alcohol material: according to the mass ratio of 5-8: 1-3: 0.01 mixing polyvinyl alcohol with the molecular weight of 1000-2000, polyvinyl alcohol with the molecular weight of 5000-8000 and a modifier.

Further, the modifier: according to the mass ratio of 3-7: 0.01 taking silane coupling agent KH-550 and nano titanium dioxide.

Further, the auxiliary agent: according to the mass ratio of 4-8: 1, mixing starch and dextrin to obtain the auxiliary agent.

Further, preparation of the carrier base: according to the mass ratio of 20-30: and 3, mixing 20-30% by mass of sodium metaaluminate solution and sodium bicarbonate in a sealed container, adjusting the pH, introducing carbon dioxide gas at 40-60 ℃, controlling the pressure of the carbon dioxide gas, vibrating the liquid while introducing the gas, aging, separating, washing and drying to obtain the carrier base material.

Further, the aging temperature in the aging step is 40-60 ℃, and the aging time is 60-90 min.

Further, in the separation washing step, the washing temperature is 30-50 ℃, and the washing times are 5-10; the pH value of the final washing wastewater is 6.8-7.3; the temperature in the drying step is 85-100 ℃, and the drying time is 4-8 h.

A preparation method of a pesticide slow-release film based on polyvinyl alcohol comprises the following steps:

(1) taking the following components in parts by weight: 10-15 parts of mixed polyvinyl alcohol material, 14-20 parts of carrier base material, 1-3 parts of pesticide avermectin, 0.5-1.8 parts of biomass charcoal, 1-3 parts of dodecyl betaine, 0.1-0.4 part of formaldehyde, 2-5 parts of glycerol, 0.2-0.5 part of auxiliary agent and 110-130 parts of water;

(2) heating water to 35-45 ℃ for heat preservation, adding a mixed polyvinyl alcohol material, a carrier base material and water for mixing and stirring, heating to 70-85 ℃, sealing and stirring, accelerating stirring, cooling, adding dodecyl betaine, stirring at room temperature to obtain a mixed solution, adding pesticide avermectin, biomass charcoal, formaldehyde and an auxiliary agent, stirring at normal temperature until the mixed solution is dissolved to obtain a mixed solution, carrying out heat preservation and stirring at 50-65 ℃, adding glycerol for mixing and stirring, carrying out vacuum degassing, uniformly spreading a drainage fluid, drying to obtain a membrane A, and then carrying out hot-pressing lamination on the membrane A and a membrane B with the same size to obtain the pesticide slow-release membrane based on polyvinyl alcohol.

In use, the surface A faces upwards on the lower surface B.

Further, the pressure of the vacuum degassing is 0.05-0.08 MPa; controlling the temperature and drying at 28-35 ℃; the thickness of the dried film is 0.16-0.45 mm

Further, the film B is prepared substantially the same as the film A except that the mixed polyvinyl alcohol material is used without adding a modifier.

In summary, due to the adoption of the technical scheme, the invention has the beneficial effects that:

the invention uses polyvinyl alcohol material, uses polyvinyl alcohol with lower molecular weight and polyvinyl alcohol with higher molecular weight to mix, forms interlaced polyvinyl alcohol main body, forms film stably, uses modifier to activate polyvinyl alcohol, and mixes nanometer titanium dioxide to provide photodegradation, uses carrier base material to make pseudo-boehmite from sodium metaaluminate solution and sodium bicarbonate, and adds sodium bicarbonate as stabilizer to combine with more carbon dioxide to form porous diameter adsorption main body, and can cooperate with active carbon to better bear pesticide, the invention uses film A which adds modifier to modify main material and film B which is not modified to hot-press and joint to form pesticide slow-release film based on polyvinyl alcohol, A face is downward, B face is upward, sunlight irradiates, nanometer titanium dioxide contained in A face provides photocatalysis effect to accelerate decomposition of pesticide in film, nanometer titanium dioxide itself can also provide assistance, the insecticidal and bacteriostatic effects of the pesticide are synergistically enhanced, the pesticide is released in a gradient manner firstly and then is released in a full gradient manner, and the slow release effect is enhanced.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A pesticide slow-release film based on polyvinyl alcohol comprises the following components in parts by weight:

10-15 parts of mixed polyvinyl alcohol material, 14-20 parts of carrier base material, 1-3 parts of pesticide abamectin, 0.5-1.8 parts of biomass charcoal, 1-3 parts of dodecyl betaine, 0.1-0.4 part of formaldehyde, 2-5 parts of glycerol, 0.2-0.5 part of auxiliary agent and 110-130 parts of water.

Mixing polyvinyl alcohol materials, namely mixing the polyvinyl alcohol with lower molecular weight and the polyvinyl alcohol with higher molecular weight, wherein the mass ratio of the polyvinyl alcohol materials to the polyvinyl alcohol with higher molecular weight is 5-8: 1-3: 0.01 is the combination of polyvinyl alcohol with the molecular weight of 1000-2000, polyvinyl alcohol with the molecular weight of 5000-8000 and a modifier.

Auxiliary agent: according to the mass ratio of 4-8: 1, mixing starch and dextrin to obtain the auxiliary agent.

Modifying agent: according to the mass ratio of 3-7: 0.01 taking silane coupling agent KH-550 and nano titanium dioxide.

Preparation of carrier base material: according to the mass ratio of 20-30: and 3, mixing 20-30% by mass of sodium metaaluminate solution and sodium bicarbonate in a sealed container, adjusting the pH to 9.2-10.3, introducing carbon dioxide gas at 40-60 ℃ at 3-8L/min, controlling the pressure of the carbon dioxide gas to be more than 0.1MPa, shaking the liquid while introducing the gas, aging, separating, washing and drying after introducing the gas for 3-6 min to obtain the carrier base material.

In the aging step, the aging temperature is 40-60 ℃, and the aging time is 60-90 min;

in the separation washing step, the washing temperature is 30-50 ℃, and the washing times are 5-10; the pH value of the final washing wastewater is 6.8-7.3.

In the drying step, the drying temperature is 85-100 ℃, and the drying time is 4-8 h.

A preparation method of a pesticide slow-release film based on polyvinyl alcohol comprises the following steps:

(1) taking the following components in parts by weight: 10-15 parts of mixed polyvinyl alcohol material, 14-20 parts of carrier base material, 1-3 parts of pesticide avermectin, 0.5-1.8 parts of biomass charcoal, 1-3 parts of dodecyl betaine, 0.1-0.4 part of formaldehyde, 2-5 parts of glycerol, 0.2-0.5 part of auxiliary agent and 110-130 parts of water;

(2) heating water to 35-45 ℃ for heat preservation, adding a mixed polyvinyl alcohol material, a carrier base material and water, mixing and stirring for 30-50 min until swelling, heating to 70-85 ℃, sealing, stirring for 20-35 min at the speed of 200-250 r/min, stirring for 30-55 min at the speed of 400-600 r/min, naturally cooling to room temperature, adding dodecyl betaine, stirring for 30-45 min at the room temperature at the speed of 300r/min to obtain a mixed solution, adding pesticide abamectin, biomass carbon, formaldehyde and an auxiliary agent, stirring at normal temperature to dissolve to obtain a mixed solution, mixing and stirring for 40-60 min at the temperature of 50-65 ℃, adding glycerol, mixing and stirring for 20-40 min, degassing in vacuum at 0.05-0.08 MPa, slowly placing the degassed material on a polytetrafluoroethylene plastic horizontal drying table for drainage and uniform expansion, controlling the temperature to 28-35 ℃ for drying, and obtaining a film A with the film thickness of 0.14-0.20 mm after control and drying, and hot-pressing and laminating the film B with the same size to obtain the pesticide slow-release film based on the polyvinyl alcohol.

Specifically, the preparation method of the film B is basically the same as that of the film A, except that no modifier is added in the mixed polyvinyl alcohol material.

In use, the surface A faces upwards on the lower surface B.