RU2057143C1 - Method for production of phosphorylated starch - Google Patents

Abstract

FIELD: textile and food industry. SUBSTANCE: initially starch is treated by urea, the process is carried out within 4-4.5 h at 80-90 C. Thus obtained product is cooled to room temperature and is mixed with aqueous solution of hydrogen peroxide. Then thus prepared mixture is heated at 60-70 within 1-2 h, cooled to room temperature and treated by phosphorous anhydride. The latter process is carried out within 1-7 h at 20-70 C, molar ratio of starch, urea, hydrogen peroxide and phosphorous anhydride being 1: (0.048-0.435): (0.0046-0.0483):(0.0013-0.161) respectively. EFFECT: improves efficiency of method. 1 tbl

Description

 The invention relates to a method for producing phosphorylated starch, used as an additive that increases the strength properties of paper and paperboard made from wood pulp, waste paper and cellulose. Phosphorylated starch is also widely used in the textile, food industry and other sectors of the economy.

 A known method of phosphorylation of starch in an aqueous medium with phosphorus oxychloride [1] However, the preparation of the target product is associated with the loss of starch due to dissolution, the presence of a large amount of wastewater, as well as laborious operations of filtering a suspension of starch in water and drying it.

 In addition, the phosphorylation process according to these methods is carried out at a strict pH of the medium, which also complicates the production technology.

A known method of phosphorylation of starch with tetrapolyphosphoric acid. However, this method involves the use of expensive reagents (dimethylformamide, tributylamine, alcohol) [2]
Known method phosphoric anhydride phosphorylation of starch in an aqueous medium [3] in which a suspension of starch in water was added a solution of soda and phosphoric anhydride, the mixture was heated at 60-70 ^{° C,} acidified and filtered, the product washed and dried. Since phosphoric anhydride interacts vigorously with water, the phosphorylating agent in this case is essentially the product of the interaction of phosphoric anhydride with water, which is a much weaker phosphorylating agent than phosphoric anhydride, and cannot ensure complete phosphorylation. In addition, obtaining the target product by this method is associated with the loss of starch and phosphorylating agent due to dissolution in water, the presence of a large amount of wastewater, as well as the laborious operations of filtering a suspension of starch in water and drying it.

A known method for producing phosphorylated starch by treating starch with phosphoric anhydride and an alkaline agent by heating. The dry starch is first treated with an alkaline agent dry 0.5-2.0 hours at 30-100 ^{° C} and then gradually introduced phosphorous anhydride and the mixture was incubated 0.5-2.0 hr at 80-100 ^{° C} with a molar ratio of starch, alkali agent and phosphoric anhydride equal to 0.023-15.4: 0.007-1.2: 0.004-0.57. As an alkaline agent, potassium hydroxide or soda is used.

 Starch alcoholate formed by the interaction of starch with an alkaline agent, being a highly reactive compound, vigorously interacts with phosphoric anhydride, providing exhaustive phosphorylation.

 Conducting phosphorylation of starch under the above conditions eliminates: loss of starch during dissolution, waste water, labor-intensive operations and drying, and also allows to obtain products with a high degree of phosphorylation.

 It was experimentally established that solutions of brewed phosphorylated starch obtained by this method do not withstand autoclaving for 20 minutes at 1 atm.

Closest to the proposed is a method for producing phosphorylated starch by treating dry starch with a mixture of phosphoric anhydride and urea in a mass ratio of 1: 1-2 for 50-90 min [4]
The purpose of the invention is the creation of a method for producing modified starch, the brewed solutions of which withstand autoclaving and can be used as gelling agents.

 Gelling agents are widely used both in the paper industry for the manufacture of paper, as well as in agriculture for the germination of seeds of various plants and as substitutes for expensive and inaccessible agar.

This object is achieved a method of producing phosphorylated starch comprising treating a starch urea and phosphoric anhydride, wherein the starch is first treated with urea at 80-90 ^{° C} for 4-4.5 h then cooled to room temperature, the product is mixed with an aqueous solution of hydrogen peroxide, a mixture of is heated 1-2 hours at 60-70 ^{° C} followed by cooling to room temperature and treated with phosphorus pentoxide at 20-70 ^{° C} for 1-7 h, the molar ratio of starch: urea: hydrogen peroxide: selecting phosphoric anhydride dissolved in the ranges 1: (0,048-0,435) :( 0,0046-0,0483) :( 0,0013-0,161).

 Giving the modified starch the properties of a gelling agent can be achieved by introducing urea into the starch, then oxidizing it with hydrogen peroxide and only then modifying it with phosphoric anhydride. Since urea has several nucleophilic centers, it easily reacts with glucose residues in starch, forming the usual adducts of the interaction of carbonyl compounds with amines, as well as with starch molecules, which greatly facilitates the oxidation process. The introduction of a phosphate group after oxidation can increase the dispersion of the brewing product.

 The proposed method is simple to implement, does not require the use of expensive reagents and sophisticated equipment. The whole process is carried out in one unit, which is a container with a stirrer. It can serve as the basis for creating a continuous process for the production of modified starches. The process is non-waste. As a raw material, you can use starch of various origin (potato, corn, etc.), since the properties obtained by the proposed method for modifying starches are the same.

 The proposed method allows you to enter into the starch molecule various amounts of organically bound phosphorus and thus obtain modified starches with different properties that meet the needs of various sectors of the economy.

PRI me R 1. 250 g (1.5 mol) of starch is placed in a reactor, add 20 g (0.3 mol) of urea and the mixture is kept for 4.5 hours at 85 ^about C. To the product cooled to room temperature add 50 ml of 5% hydrogen peroxide (0.07 mol). Heated for 1 h at 70 ^about C. To the chilled product, phosphorus pentoxide 3.7 g (0.04 mol) is added. The reaction mixture was heated for 1 hour at 70 ^C. Yield 245 g (98%); the content of bound phosphorus 1% viscosity of the product (1% solution) 3 pass / s).

PRI me R 2. 100 g (0.62 mol) of corn starch are loaded into the reactor and 2 g (0.03 mol) of urea are added with stirring. The reaction mixture was kept at 80 ^{° C} for 4 h and cooled to room temperature. Thereto was added 20 ml of 4% hydrogen peroxide (0.023 mol), heated for 1 hour at 70 ° ^C. To the cooled product was added 1.2 g (0.008 mol) of phosphorus pentoxide under stirring. The mixture was kept 1.5 hours at 60 ^C. Yield 96 g (96%); the content of bound phosphorus 0.5% viscosity of a 1% solution of 4 pass / s.

PRI me R 3. In the reactor is placed 1000 g (6.2 mol) of potato starch and 80 g (1.3 mol) of urea. Heat for 4.5 h at 80 ^° C then cooled to room temperature and the product is added 200 ml of a 3% hydrogen peroxide (0.2 mol) are heated for 1 hour at 70 ^C. After the oxidation is added 68 g of ( 0.48 moles) of phosphoric anhydride was heated for 2.5 hours at 50 ^C. Yield 960 g (98%); the viscosity of a 1% solution of 1.9 pass / s; the content of bound phosphorus 2.8%
PRI me R 4. 100 g of corn starch (0.62 mol) is placed in a reactor and 16 g (0.27 mol) of urea are added. The mixture was heated for 4 hours at 80 ^° C, cooled to room temperature, the product was added 20 ml of 3% (0.02 mol) of hydrogen peroxide and heated for 2 hours at 60 ° ^C. Then was added 2.5 g of P ₂ O ₅ (0, 02 mol) with stirring. The mixture was allowed to stand for 5 hours at 35 ^C. Yield 97 g (98%); the content of bound phosphorus is 1%; the viscosity of a 1% solution is 2.5 pass / s.

PRI me R 5. In the reactor, 100 g of potato starch (0.62 mol) are mixed with 8 g (0.13 mol) of urea. The mixture was heated at 85 ^{° C} for 4.5 hours. To the cooled to room temperature, the product was added 5 ml 20% hydrogen peroxide (0.03 mol). The mixture was heated with stirring for 1 hour at 70 ^C. The product was cooled to room temperature and added with stirring 2.5 g of P ₂ O ₅ (0.017 mol). The mixture was heated for 2 hours ^at 50 ° C; yield 95 g (95%); the content of bound phosphorus is 1% viscosity of a 1% solution of 3 pass / s.

PRI me R 6. In the reactor load 25 g of corn starch (0.15 mol), add 1.5 g (0.025 mol) of urea. The mixture was heated at ⁹⁰ ° C for 4 hours. Then cooled to room temperature, the product was added with stirring 5 ml of 5% (0.007 mol) of hydrogen peroxide. The mixture was heated 1.5 hours at 60 ^C. Cool to room temperature and added with stirring 0.3 g of P ₂ O ₅ (0.002 mol). The mixture was left at room temperature for 7 hours. Yield 23 g (92%); the viscosity of a 1% solution of 2.5 pass / s; the content of bound phosphorus 0.5%
PRI me R 7. 10 g (0.062 mol) of corn starch and 0.8 g (0.013 mol) of urea are placed in a reactor. The mixture was heated with stirring for 4 hours at 90 ^° C, cooled to room temperature, the product was added 2 ml of 5% hydrogen peroxide (0.003 mol). Heat the mixture 1.5 h at 60 ^C. The mixture is cooled to room temperature and add 0.75 g (0.005 mol) of P ₂ O ₅ under stirring. Maintain the product at 30 ^about C for 5 hours. Yield 95 g (95%); the content of bound phosphorus is 9%; the viscosity of a 1% solution is 1.5 pass / s.

EXAMPLE EXAMPLE 8 To 100 g (0.62 mol) potato starch was added 16 g (0.27 mol) of urea and the mixture was heated for 4.5 hours at 85 ^° C, cooled to room temperature, the product was added 20 ml of 2% (0.01 mol) hydrogen peroxide with stirring and incubated for 1 h at 70 ^about C, cooled and introduced with stirring 15 g (0.1 mol) of P ₂ About ₅ . Heated at 50 ^about C for 2.5 hours. Yield 98 g (98%); the content of bound phosphorus is 18%; the viscosity of a 1% solution is 1.5 pass / s.

 Data on the molar ratio of components are presented in the table.

 PRI me R 9. Laboratory tests of the use of modified starch obtained by the proposed method as a gelling agent for seed germination, on callus of tobacco, potatoes growing on the PMCI medium at a total concentration of gelling agent of 0.8%, were carried out. if 0.8 g of agar is taken per 1000 ml of medium, then using modified starch in the preparation of the medium, 0.2 g of agar and 0.6 g of starch are taken, i.e. the ratio of agar: modified starch is 1: 3. The following results were obtained: 1. The content of P 1%. The gelling properties are satisfactory. The growth of biomass is normal. 2. The content of P is 2.8% Callus potato Solanum tuberogum. Variety "Glow". Good callus growth is noted, light, dense. The consistency of the medium is satisfactory. 3. Content P 9%. Consistency is good. Callus grows well.

Claims (1)

METHOD FOR PRODUCING PHOSPHORIATED STARCH, comprising treating starch with urea and phosphoric anhydride, characterized in that the starch is first treated with urea at 80 - 90 ^° C for 4 - 4.5 hours, then the product cooled to room temperature is mixed with an aqueous solution of hydrogen peroxide, mixture heated for 1 - 2 hours at 60 - 70 ^o C, followed by cooling to room temperature and treated with phosphorus pentoxide at 20 - 70 ^o C for 1 - 7 h, the molar ratio of starch: urea: hydrogen peroxide: phosphorus pentoxide vybi ayut in the range 1: (0.048 - 0.435) (0.0046 - 0.0483) (0.0013 - 0.161).

Images