CN105254812A - Grafted starch slurry preparation method based on enzymatic cascade reaction - Google Patents

Abstract

The invention discloses a method for preparing grafted starch slurry based on an enzymatic cascade reaction. In the method, a co-modification technology is first used to cross-link lactic acid oxidase and horseradish peroxidase to form a co-modified enzyme; Starch is made into a certain concentration solution, and lactic acid and acrylic acid monomers are added, and the temperature is raised to 70-95°C for gelatinization for 0.1-1 hour, then the temperature is adjusted to 40-80°C, and finally the co-modified enzyme is added to the starch solution to keep warm Reaction 1-10 hours. The method of the present invention realizes the biological preparation of grafted starch through enzymatic cascade reaction, the graft polymerization reaction is easy to control, the product has the characteristics of synthetic polymer and starch, and the prepared grafted starch has the adhesion to fiber: cotton>70N, polyester >90N; serous film bending resistance >500 times; serous film strength: 20.0-33.5N/mm ² , serous film elongation: 3.5-5.9%, serous viscosity stability: >90%.

Description

A kind of preparation method of grafted starch size based on enzymatic cascade reaction

technical field

The invention relates to a method for preparing grafted starch size based on enzymatic cascade reaction, which belongs to the technical field of textiles.

Background technique

Starch is a natural polysaccharide that is abundant, renewable, biodegradable, low-cost, and widely available worldwide. However, compared with synthetic polymers, it has some disadvantages in terms of performance, such as its thermal stability, solubility, ion exchange and so on. The chemical modification of starch by oxidation, hydrolysis, esterification and grafting has been extensively studied. Graft modification of starch is a very effective means to change the physical and chemical properties of starch. By introducing a flexible chain into the rigid main chain of starch, its film-forming flexibility, thermal stability, metal ion binding ability, and resistance to Biocorrosion and other properties enhance its industrial applicability and expand its application range.

Grafted starch is mainly prepared by graft copolymerization method initiated by free radicals, and free radical initiation can be divided into chemical initiator initiation method and Co ⁶⁰ ray, light, microwave radiation and other physical initiation methods. When chemical initiators are initiated, chemical reagents often remain in the reactants, which brings troubles to subsequent processing, but they are widely used because of their easy availability and easy operation, and the research is also extensive and in-depth. The main ones that have been studied are oxidation systems such as cerium salts (such as cerium ammonium nitrate), persulfates, manganese salts, potassium permanganate and azobisisobutyronitrile, and redox systems such as H ₂ O ₂ -FeSO ₄ To initiate graft copolymerization of starch and acrylonitrile, acrylic acid, acrylamide, methyl (meth)acrylate, butyl acrylate, styrene, vinyl acetate, dimethyl fumarate and other monomers and combinations of different monomers . CN102643390B discloses a self-assembled oxidation-reduction initiation system, which rapidly initiates cationic starch at room temperature and simultaneously ternally grafts and copolymerizes cationic starch with hydrophilic, lipophilic and amphiphilic monomers. ; CN102329404B discloses a composite denatured grafted starch for textile size and its preparation method, in which acrylamide, acrylic acid and vinyl acetate ternary mixed monomers are grafted on starch macromolecules under the condition of alcohol solvent. CN101353393B discloses a method for preparing grafted starch radical polymerization with improved side branch formation; CN101481441B discloses a method for preparing acrylic acid monomer grafted starch slurry by chemical initiator triggering instantaneous polymerization; CN100402567C discloses a method for grafting starch with ethanol A method for preparing grafted starch initiated by a chemical initiator as a solvent; CN102051015A discloses a method for synthesizing methyl acrylate grafted starch slurry by ultrasonic microwave method; CN102212169B discloses a method for firstly irradiating 60Co-γ to obtain irradiation Starch, then irradiated starch is treated with debranching enzyme, and then the method for synthesizing grafted starch slurry with α-olefin reaction; CN101735392B discloses a kind of acrylic acid, methacrylic acid that is beneficial to microwave radiation and chemical initiator to work together The preparation method of butyl ester grafted corn starch.

Warp sizing is a key process in textile production, which directly affects weaving efficiency and product quality. In order to adapt to the weaving requirements of high-speed looms and fine-count high-density fabrics, the sizing materials (sizing materials) used must have good film-forming properties, flexibility, wear resistance, buckling fatigue resistance, strong elongation and elasticity, and require good fiber It has good adhesion performance. Native starch and general modified starch are difficult to meet this requirement, so a large amount of polyvinyl alcohol size with poor desizing performance and difficult to biodegrade has to be used in textile warp yarn sizing. In order to improve the performance of starch sizing and increase the proportion of substituted polyvinyl alcohol sizing, grafted modified starch has been used as textile sizing at home and abroad, and it has become a research hotspot for a time. Acrylic size has good film-forming property, soft size film, no pollution to the environment, and has been widely used in warp yarn sizing. However, acrylic size has a large moisture absorption and reviscous property, so it cannot be used alone as the main size, but can only be used as an auxiliary size in the main size. Compared with native starch, acrylic acid grafted starch has lower viscosity, better size film strength and toughness, and higher film storage modulus, which avoids the disadvantages of raw starch size such as brittleness, hardness, and high viscosity, and can meet the needs of polyester/cotton blended yarns. Sizing requirements, can be used as sizing size. In addition, the starch is pre-treated and then grafted with acrylic acid, the size film performance of the grafted starch is better.

Although grafted starch has been highly valued and a lot of research has been carried out, various existing synthetic methods have many defects such as harsh grafting conditions and difficult control of the grafting process, especially due to the composition and structure of starch itself. Limitation (mainly the impact of amylopectin), the film-forming performance of the product is not significantly improved, which has a strong impact on its application effect in film-forming materials. For example, in textile sizing, the current grafted starch cannot completely or in a high proportion replace the hard-to-biodegrade polyvinyl alcohol sizing. Therefore, how to break through the bottleneck of grafted starch synthesis method and molecular structure design is an urgent task for the basic research of this kind of materials.

The invention provides a method for preparing grafted starch slurry based on an enzymatic cascade reaction, that is, co-modification technology is used to cross-link lactic acid oxidase and horseradish peroxidase to form a co-modification enzyme, and then combine it with Starch, lactic acid, and acrylic monomers are mixed and reacted under certain conditions. Lactic acid oxidase is used to catalyze lactic acid to generate hydrogen peroxide, and then acrylic monomers are grafted into the molecular structure of starch under the action of horseradish peroxidase. A starch-grafted polyacrylic polymer that can be used as a textile size is obtained. The biological method for preparing grafted starch proposed by the invention is an environment-friendly method for preparing grafted starch.

Contents of the invention

The invention provides a kind of grafted starch slurry preparation method based on enzymatic cascade reaction, and the method comprises the following steps:

(1) Preparation of co-modified enzymes: Dissolve lactate oxidase and horseradish peroxidase in deionized water, add natural biological cross-linking agent genipin, lactate oxidase, horseradish peroxidase and genipin in the system The average mass concentration is 0.01-10%, 0.01-15% and 1-5%, respectively, and then react at 30-55°C for 1-8h; after the reaction, the reaction solution is cooled to room temperature for use;

(2) Preparation of grafted starch: the starch is made into a 10-30% mass concentration solution, and 0.1-2% mass concentration lactic acid and 1-20% mass concentration acrylic monomer are added, and the temperature is raised to 70-95°C for gelatinization of 0.1 After -1 hour, adjust the temperature to 40-80°C;

(3) Add the co-modified enzyme solution prepared in step (1) to the mixed starch solution in step (2), and then keep it warm at 40-80°C for 1-10 hours; after the reaction, cool down to room temperature to obtain starch grafting Polyacrylic polymer.

The starch used to prepare the starch-grafted polyacrylic acid polymer can be cereal starch, potato starch and modified starch or a combination thereof. Cereal starch includes corn starch, wheat starch; potato starch includes tapioca starch, sweet potato starch, potato starch, konjac starch, cana starch, etc.; modified starch includes cationic starch, carboxymethyl starch, oxidized starch, acid-thinned starch, hydroxyalkane Base starch, phosphate starch, acetate starch.

Acrylic monomers include acrylic acid, methacrylic acid, acrylamide, acrylonitrile, vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate .

The concentrations of lactate oxidase, horseradish peroxidase and genipin are preferably 0.01-1%, 0.01-1% and 1-2%.

The preparation process of the co-modified enzyme is preferably reacted at 30-40° C. for 6-8 hours.

The starch concentration is preferably preferably 10-15%.

The added concentration of the lactic acid and acrylic monomers is preferably 1-2% and 5-10%.

The method of the invention realizes the biological preparation of grafted starch through enzymatic cascade reaction, the graft polymerization reaction is easy to control, the product has the characteristics of synthetic polymer and starch, can be used for textile size, and has good adhesion to fibers and elasticity of the size film Good elongation and stable slurry viscosity.

detailed description

Embodiment 1 preparation method of grafted starch slurry based on enzymatic cascade reaction

(1) Preparation of co-modified enzymes: Dissolve lactate oxidase and horseradish peroxidase in deionized water, add natural biological cross-linking agent genipin, lactate oxidase, horseradish peroxidase and genipin in the system The average mass concentration is 0.01, 15% and 5% respectively, and then react 1 at 30°C; after the reaction, the reaction solution is lowered to room temperature for use;

(2) Preparation of grafted starch: the corn starch is made into a mass concentration of 10%, and 2% mass concentration of lactic acid and 1% mass concentration of acrylic monomer are added, and the temperature is adjusted to 80°C after gelatinization for 0.1 hour at 70°C. ℃;

(3) Add the co-modified enzyme solution prepared in step (1) to the mixed starch solution in step (2), and then keep it warm at 40°C for 10 hours; after the reaction, cool it down to room temperature to obtain starch-grafted polyacrylic acid polymer thing.

Acrylic monomers include acrylic acid, methacrylic acid, acrylamide, acrylonitrile, vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate or a combination thereof.

The grafting rate of the prepared grafted starch is 50-60%, and the grafting efficiency is 80-90%. Adhesion to fiber: cotton > 70N, polyester >90N; serous film flex resistance > 500 times; serous film strength: 20.0-30.5N/mm ² , serous film elongation: 3.5-5.5%, slurry viscosity stability : >90%.

Embodiment 2 preparation method of grafted starch slurry based on enzymatic cascade reaction

(1) Preparation of co-modified enzymes: Dissolve lactate oxidase and horseradish peroxidase in deionized water, add natural biological cross-linking agent genipin, lactate oxidase, horseradish peroxidase and genipin in the system The average mass concentration was 10%, 0.01% and 1%, respectively, and then reacted at 55°C for 8h; after the reaction, the reaction solution was lowered to room temperature for use;

(2) Preparation of grafted starch: make potato starch into 30% mass concentration, add 0.1% mass concentration lactic acid and 20% mass concentration acrylic monomer, heat up to 95°C for gelatinization for 1 hour, then adjust the temperature to 40°C;

(3) Add the co-modified enzyme solution prepared in step (1) to the mixed starch solution in step (2), and then keep it warm at 80°C for 1 hour; after the reaction, cool down to room temperature to obtain starch-grafted polyacrylic acid polymer thing.

The grafting rate of the prepared grafted starch is 52-64%, and the grafting efficiency is 85-90%. Adhesion to fiber: cotton > 80N, polyester >90N; size film flex resistance > 500 times; size film strength: 25.0-30.6N/mm ² , size film elongation: 3.9-5.5%, size viscosity stability : >92%.

Embodiment 3 preparation method of grafted starch slurry based on enzymatic cascade reaction

(1) Preparation of co-modified enzymes: Dissolve lactate oxidase and horseradish peroxidase in deionized water, add natural biological cross-linking agent genipin, lactate oxidase, horseradish peroxidase and genipin in the system The average mass concentration was 0.5%, 10% and 2%, respectively, and then reacted at 45°C for 2 hours; after the reaction, the reaction solution was lowered to room temperature for use;

(2) Preparation of grafted starch: the starch is made into a mass concentration solution of 20% concentration, and 0.4% mass concentration lactic acid and 14% mass concentration acrylic monomer are added, the temperature is raised to 85° C. after gelatinization for 0.5 hour, and the temperature is adjusted to 60°C;

(3) Add the co-modified enzyme solution prepared in step (1) to the mixed starch solution in step (2), and then keep it warm at 60°C for 8 hours; after the reaction, cool it down to room temperature to obtain starch-grafted polyacrylic acid polymer thing.

The grafting rate of the prepared grafted starch is 58-64%, and the grafting efficiency is 80-90%. Adhesion to fiber: cotton > 90N, polyester >90N; size film flex resistance > 625 times; size film strength: 25.0-30.5N/mm ² , size film elongation: 4.1-5.5%, size viscosity stability : >92%.

Embodiment 4 preparation method of grafted starch slurry based on enzymatic cascade reaction

(1) Preparation of co-modified enzymes: Dissolve lactate oxidase and horseradish peroxidase in deionized water, add natural biological cross-linking agent genipin, lactate oxidase, horseradish peroxidase and genipin in the system The average mass concentration was 8.5%, 5% and 3%, respectively, and then reacted at 50°C for 2 hours; after the reaction, the reaction solution was lowered to room temperature for use;

(2) Preparation of grafted starch: starch is made into 25% mass concentration solution, and 1.2% mass concentration lactic acid and 14.3% mass concentration acrylic acid monomer are added, and the temperature is adjusted to 50° C. after gelatinization for 0.4 hours at 75° C. ℃;

(3) Add the co-modified enzyme solution prepared in step (1) to the mixed starch solution in step (2), and then keep it warm at 70°C for 2 hours; after the reaction, cool down to room temperature to obtain starch-grafted polyacrylic acid polymer thing.

The grafting rate of the prepared grafted starch is 50-60%, and the grafting efficiency is 85-90%. Adhesion to fiber: cotton > 70N, polyester >90N; size film flex resistance > 500 times; size film strength: 30.0-33.5N/mm ² , size film elongation: 4.2-5.9%, size viscosity stability : >90%.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (7)

1. a method for preparing grafted starch slurry based on enzymatic cascade reaction, the method may further comprise the steps: (1) Preparation of co-modified enzymes: Dissolve lactate oxidase and horseradish peroxidase in deionized water, add natural biological cross-linking agent genipin, lactate oxidase, horseradish peroxidase and genipin in the system The average mass concentration is 0.01-10%, 0.01-15% and 1-5%, respectively, and then react at 30-55°C for 1-8h; after the reaction, the reaction solution is cooled to room temperature for use; (2) Preparation of grafted starch: prepare the starch with a mass concentration of 10-30%, add 0.1-2% lactic acid and 1-20% acrylic monomer, heat up to 70-95°C and gelatinize for 0.1-1 hour After that, adjust the temperature to 40-80°C; (3) Add the co-modified enzyme solution prepared in step (1) to the mixed starch solution in step (2), and then keep it warm at 40-80°C for 1-10 hours; after the reaction, cool down to room temperature to obtain starch grafting Polyacrylic polymer. 2. the described preparation method of claim 1 is characterized in that starch can be cereal starch, potato starch and its modified starch or its combination; Cereal starch comprises corn starch, wheat starch; Potato starch comprises tapioca starch, sweet potato Starch, potato starch, konjac starch, canna starch, etc.; modified starch includes cationic starch, carboxymethyl starch, oxidized starch, acid-thinned starch, hydroxyalkyl starch, phosphate starch, acetate starch. 3. The preparation method according to claim 1, wherein the acrylic monomer comprises acrylic acid, methacrylic acid, acrylamide, acrylonitrile, vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, methyl acrylate, methyl acrylate, ethyl methacrylate, butyl methacrylate or combinations thereof. 4. The preparation method according to claim 1, characterized in that the concentrations of the lactate oxidase, horseradish peroxidase and genipin are preferably 0.01-1%, 0.01-1% and 1-2%. 5. The preparation method according to claim 1 or 4, characterized in that the preparation process of the co-modified enzyme is preferably reacted at 30-40°C for 6-8h. 6. The preparation method according to claim 1 or 4, characterized in that the starch concentration is preferably 10-15%. 7. The preparation method according to claim 1, characterized in that the added concentration of the lactic acid and acrylic monomers is preferably 1-2% and 5-10%.