CN-121991289-A - High-hydroscopicity anti-freezing water-retaining agent with urea slow-release function, and preparation method and application thereof

Abstract

The invention relates to the technical field of high polymer materials, and in particular discloses a preparation method and application of a super-absorbent anti-freezing water-retaining agent with a urea slow-release function. The preparation method comprises the steps of adding a cross-linking agent, a catalyst, urea, a photoinitiator and a polysaccharide solution into an aqueous solution of potassium acrylate and acrylamide, stirring, and performing photoinitiated polymerization, so that the water-retaining agent with excellent water absorption, water retention, circulation stability, soil freezing resistance and slow release performance is prepared by a one-pot method, and has wide application prospects in the agricultural field.

Inventors

• LIU YUETAO
• Zhang Jialue
• GAO CHUANHUI
• WANG CHUANXING
• ZHANG NA
• WU YUMIN

Assignees

• 青岛明聚新材料有限公司
• 青岛科技大学

Dates

Publication Date

20260508

Application Date

20260302

Claims (10)

1. 1. The preparation method of the high-hydroscopicity anti-freezing water-retaining agent with the urea slow-release function is characterized by comprising the following steps of: Uniformly mixing acrylate, acrylamide, polysaccharide solution and urea in a solvent, and carrying out photopolymerization in the presence of a cross-linking agent, a photoinitiator and a catalyst to obtain the high-hydroscopicity anti-freezing water-retaining agent; Wherein the molar ratio of the acrylic acid salt to the urea is 1 (0.02-0.26).
2. 2. The preparation method of the super absorbent anti-freezing water-retaining agent with the urea slow-release function, which is characterized in that the molar ratio of the acrylate to the acrylamide is 1 (0.1-1).
3. 3. The method for preparing the super absorbent anti-freezing water-retaining agent with the urea slow-release function according to claim 1, wherein the acrylic acid salt is potassium acrylate.
4. 4. The preparation method of the super absorbent anti-freezing water-retaining agent with the urea slow-release function as claimed in claim 1, wherein the mass ratio of the polysaccharide solution to the urea is (5-12) 1 or (5.14-10.28) 0.9; Or the concentration of the polysaccharide solution is 1-20wt%.
5. 5. The method for preparing the super absorbent anti-freezing water-retaining agent with the urea slow-release function according to claim 1, wherein the polysaccharide solution is selected from one of carboxymethyl guar gum, carboxymethyl chitosan, carboxymethyl cellulose potassium and sodium alginate.
6. 6. The method for preparing the super absorbent anti-freezing water-retaining agent with the urea slow-release function according to claim 1, wherein the cross-linking agent is at least one selected from N, N '-methylene bisacrylamide, N' - (1, 2-dihydroxyethylene) bisacrylamide and polyethylene glycol bisacrylate; Or the dosage of the cross-linking agent is 0.01-0.05wt% of the total mass of the acrylate and the acrylamide; or, the catalyst is at least one selected from 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide; Or the catalyst is 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide, wherein the molar ratio of acrylic acid to 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide is 2 (0.5-1.5): 0-1.5.
7. 7. The method for preparing the super absorbent anti-freezing water retention agent with the urea slow release function according to claim 1, wherein the photoinitiator is one selected from 2-hydroxy-4' - (2-hydroxyethylamino) -2-methyl propiophenone, 2-azo bis (2-methylpropyl-mi) dihydrochloride and 2,4, 6-trimethylbenzoyl phenyl ethyl phosphate; Or the dosage of the photoinitiator is 0.8-1.2wt% of the total mass of the acrylate and the acrylamide.
8. 8. The preparation method of the super absorbent anti-freezing water-retaining agent with the urea slow-release function as claimed in claim 1, wherein the photopolymerization reaction condition is that the power of an ultraviolet lamp is 1-5KW and the wavelength is 365nm; Or the photopolymerization reaction time is 15-30min.
9. 9. The super-absorbent anti-freezing water-retaining agent with urea slow-release function prepared by the method of any one of claims 1 to 8.
10. 10. The application of the super absorbent anti-freezing water-retaining agent with urea slow release function in the agricultural field.

Description

High-hydroscopicity anti-freezing water-retaining agent with urea slow-release function, and preparation method and application thereof Technical Field The invention belongs to the technical field of high polymer materials, and relates to a preparation method and application of a high-hydroscopicity anti-freezing water-retaining agent with a urea slow-release function. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. In the fields of agriculture, forestry, gardening and the like, the water-retaining agent is widely applied, and in the use process, the water resource problem is considered, and the water and fertilizer loss phenomenon is considered. The release rate of the common instant fertilizer in the soil is high, so that the loss phenomenon is serious due to the enrichment of nutrients in the soil in a short time, the fertilization frequency and the fertilization amount are required to be increased to meet the fertility requirements of crops, and serious environmental problems and economic burden are caused. The water-retaining and controlled-release fertilizer based on cellulose, halloysite and cyclodextrin is disclosed, and the slow release of the fertilizer is realized by embedding urea into halloysite and wrapping the urea in a polymer. However, the fertilizer in the material is only physically embedded in a small molecular form, so that the release rate is unstable, the release period is short, the polymer network structure is simple, the water absorption performance is limited, and the water retention and slow release synergistic effect in practical application is poor. The water-retaining slow-release hydrogel based on chitosan sulfonate, aminated carrageenan and phosphorylated polyvinyl alcohol is researched and disclosed, an interpenetrated three-dimensional network structure is constructed through ionic crosslinking, and the water absorption rate and urea slow-release function of 438.7 g/g of the material are endowed, but the water absorption rate of the hydrogel is lower, long-time high-temperature reaction is required, the energy consumption is higher, and the production controllability and the large-scale cost face challenges. The urea coated cellulose-based super absorbent resin is used as a skeleton, urea is coated by an calcium alginate gel layer to form a physical barrier type double-layer composite structure, but the urea is mainly released through physical embedding and diffusion paths, the slow release effect depends on the outer coating structure, and the requirements of cooperative optimization of high water absorption capacity, slow release performance and low-temperature freezing resistance are difficult to meet. Has been studied with sodium acrylate, acrylamide, 2Acrylamide2Methyl group1The propane sulfonic acid forms a first network and then is crosslinked with a second network of calcium salt and natural polysaccharide to form the super absorbent dual-network resin, but the super absorbent dual-network resin cannot meet the requirements of cooperative optimization of high water absorption capacity, slow release performance and low temperature frost resistance. Disclosure of Invention The invention aims to solve the short plates and the defects of low water absorption rate, unobvious water retention effect and limited urea slow release capability of the existing water-retaining agent in agricultural application, and develops the water-retaining agent which has simple preparation process, high economic benefit, anti-freezing effect, ultrahigh water absorption rate, high water retention, strong mechanical property, high cycle stability and slow release fertilizer capability. In order to achieve the above purpose, the present invention adopts the following technical scheme: The invention provides a preparation method of a super-absorbent anti-freezing water-retaining agent with urea slow-release function, which comprises the following steps: Uniformly mixing acrylate, acrylamide, polysaccharide solution and urea in a solvent, and carrying out photopolymerization in the presence of a cross-linking agent, a photoinitiator and a catalyst to obtain the high-hydroscopicity anti-freezing water-retaining agent; Wherein the molar ratio of the acrylic acid salt to the urea is 1 (0.02-0.26). The invention constructs a covalent grafted hybridized rigid-flexible composite three-dimensional crosslinked network structure, forms a stable network system through the cooperative crosslinking of acrylic acid, acrylamide and polysaccharide chains, and realizes multifunctional cooperative regulation and control by utilizing urea to participate in the construction of the network structure. In the invention, urea is not only used as a nit