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Pregelatinized hydroxypropyl starch and preparation method thereof

A technology of pregelatinized hydroxypropyl and gelatinized hydroxypropyl, applied in the field of starch modification, can solve the problems of accelerated propylene oxide ring-opening reaction, large amount of strong alkaline substances, loss of condensation and reflux, etc., so as to improve production efficiency , less impurity content, the effect of microbial limit control

Inactive Publication Date: 2018-06-26
HUNAN ER KANG PHARMA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But adopt the method of this patent to have following problem: 1, the basic catalyst that adopts is sodium hydroxide or potassium hydroxide, and its consumption is 12-20% of starch weight, strong basic material can not only accelerate the development of propylene oxide Ring reaction, but also accelerate the formation of by-products, such as propylene glycol, etc.
2. The amount of strong alkaline substances needed to be used in the whole reaction process is also relatively large, such as swelling agent and catalyst are strong alkali, so the corrosion of equipment and the impact on the environment are also worrying
3. Since the reaction is carried out under non-airtight conditions, and the propylene oxide and the dispersion medium isopropanol are both volatile substances, simple condensation and reflux will still cause certain losses
Therefore, in order to achieve the desired degree of product substitution, excessive propylene oxide needs to be added in the reaction, and the price of propylene oxide is relatively expensive, thus further increasing the cost of the reaction

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] Weigh 1000g of food-grade tapioca starch and place it in a pressure-resistant reactor, add 80ml of 10% acetic acid, and then add 25ml of tetramethylammonium hydroxide, and keep at 30°C for 30min to form a starch inclusion compound. Titrate the above mixed solution with sodium hydroxide solution to adjust the pH to 9.0. Dissolve 2000ml of propylene oxide solution and 15ml of 25% tetramethylammonium hydroxide solution in 3L of isopropanol, disperse them evenly and add them to the starch inclusion compound. Under the protection of high-purity nitrogen, heat to Stir and react for 4 hours at 50°C. After cooling to room temperature, add 2 times the amount of ethanol and let stand for a period of time, then centrifuge and wash 3 times, then filter, freeze-dry to obtain hydroxypropyl starch; The base starch is dissolved in hot water at a temperature of 60℃ to make a 48% water-based paste. After 250W ultrasonic treatment for 25 minutes, the water-based paste solution is atomized ...

Embodiment 2

[0038] Weigh 1000g of food-grade sweet potato starch into a pressure-resistant reactor, add 80ml of 10% acetic acid, and then add 30ml of tetramethylammonium hydroxide, and keep at 30°C for 30min to form a starch inclusion compound. Titrate the above mixed solution with sodium hydroxide solution to adjust the pH to 10.0. Dissolve 2000ml of propylene oxide solution and 18ml of 25% tetramethylammonium hydroxide solution in 3L of isopropanol, disperse them evenly and add them to the starch inclusion compound. Under the protection of high-purity nitrogen, heat to Stir and react at 50°C for 4 hours. After cooling to room temperature, add 2 times the amount of ethanol and let stand for a period of time, then centrifuge and wash 3 times, then filter and freeze-dry to obtain hydroxypropyl starch; the prepared hydroxypropyl starch The base starch is dissolved in hot water at a temperature of 60℃ to make a 48% aqueous paste. After 250W ultrasonic treatment for 25 minutes, the aqueous pas...

Embodiment 3

[0041] Weigh 1000g of food-grade tapioca starch and place it in a pressure-resistant reactor, add 80ml of acetic acid with a mass fraction of 10%, then add 40ml of tetramethylammonium hydroxide, and keep at 30°C for 30min to form a starch inclusion compound. Titrate the above mixed solution with sodium hydroxide solution to adjust the pH to 11.0. Dissolve 2000ml of propylene oxide solution and 15ml of 10% tetramethylammonium hydroxide solution in 3L of isopropanol, disperse them evenly and add them to the starch inclusion compound. Under the protection of high-purity nitrogen, heat to Stir and react for 4 hours at 50°C. After cooling to room temperature, add 2 times the amount of ethanol and let stand for a period of time, then centrifuge and wash 3 times, then filter, freeze-dry to obtain hydroxypropyl starch; The base starch is dissolved in hot water at a temperature of 60℃ to make a 48% water-based paste. After 250W ultrasonic treatment for 25 minutes, the water-based paste ...

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Abstract

The invention discloses a pregelatinized hydroxypropyl starch and a preparation method thereof. The preparation method comprises the following steps: 1, pretreatment and activation of starch; 2, hydroxypropylation of starch; 3, refining of hydroxypropyl starch; and 4, preparation and refining of the pregelatinized hydroxypropyl starch. According to the method, before a hydroxypropylation reactionof the starch, the starch is subjected to clathration; i.e., the molecules of one catalyst are included in starch molecules so as to destroy a crystal structure of a crystal region in the starch and allow the internal structure of starch milk to further swell; so the catalyst can contact with more starch reaction active sites, and the degree of hydroxypropylation is effectively increased to 8.0% or more. The pregelatinized hydroxypropyl starch prepared by using the method is high in the content of effective components, low in impurity content and controlled in microbial limit, and reaches thestandard for pharmaceutic adjuvant. The preparation method is simple to operate, mild in reaction conditions and suitable for industrial production.

Description

Technical field [0001] The invention belongs to the field of starch modification, and relates to a modified starch, in particular to a preparation method of pregelatinized hydroxypropyl starch. Background technique [0002] Starch is one of the largest natural polymers produced in nature, and has a very wide range of industrial uses. There are two types of starch: amylose and amylopectin. Amylose contains several hundred glucose units, and amylopectin contains several thousand glucose units. Amylose accounts for 20%~26% of natural starch, which is soluble, and the rest is amylopectin. However, starch is composed of α-(1,4)-linked D-glucose, which contains a large number of active hydroxyl groups on the molecule, which is easy to form intramolecular and intermolecular hydrogen bonds. Therefore, starch itself contains a relatively high clean area, which is difficult to dissolve and difficult to dissolve. It cannot be melt-processed, and it is not easy to interact with chemical o...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08B31/12
CPCC08B31/12
Inventor 帅放文王向峰章家伟
Owner HUNAN ER KANG PHARMA