Preparation method of hydroxypropyl starch

A technology of hydroxypropyl starch and hydroxypropylation, which is applied in the field of preparation of hydroxypropyl starch, can solve the problems such as difficult exposure of reactive points of starch reaction, poor solubility of starch and catalyst, low efficiency of starch hydroxypropylation, and the like, Achieve the effect of shortening the reaction time, mild conditions, and increasing the degree of substitution

Inactive Publication Date: 2010-07-07
鲁郑全 +3
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

But adopt the method of this patent to have the following problems: 1, the dispersing agent that adopts is non-polar solvent, and starch and catalyst solubility are poor, and the reactive active point of starch is difficult to expose; 2, reaction is to carry out under high temperature and airtight condition Yes, the pressure in the reaction vessel is high, which not only puts forward higher requirements for the production equipment, but also has certain safety hazards; 3. During the hydroxypropylation process, the starch mixture needs to be kept in water for a long time under continuous stirring. The nucleophilic reaction between the alkoxy anion and the epoxy group can only be completed after 812 hours of soaking. During this process, the viscosity of the system is high, time-consuming and energy-consuming, and the efficiency of starch hydroxypropylation is low.

Method used

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  • Preparation method of hydroxypropyl starch
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  • Preparation method of hydroxypropyl starch

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] The pre-swelling and hydroxypropylation reactions in this example were carried out in a reaction vessel equipped with an electric stirrer, a thermometer and a reflux condenser.

[0038] Measure 135ml of 90% ethanol solution into the reaction vessel, heat up to 30°C, add 0.6g (3% of the starch weight) sodium hydroxide into it and stir until completely dissolved; weigh 20g of cornstarch and add it into the reaction vessel, stir And heating, when the temperature rises to 78 ° C, there is a reflux phenomenon, after the heat preservation reaction for 120 minutes, the temperature is cooled to room temperature; suction filtration, washing with 300 ml of 95% ethanol in 4 times, to obtain pre-swelled starch in the form of particles;

[0039] Put the obtained pre-swelled starch into the reaction container, and add 185ml 90% ethanol solution, 3g sodium hydroxide, and 100ml propylene oxide, stir and heat, when the temperature rises to 50°C, there will be a reflux phenomenon, and the...

Embodiment 2

[0041] The pre-swelling and hydroxypropylation reactions in this example were carried out in a reaction vessel equipped with an electric stirrer, a thermometer and a reflux condenser.

[0042] Measure 100ml of 85% ethanol solution into the reaction vessel, add 0.6g (4% of starch weight) potassium hydroxide into it and stir until completely dissolved; weigh 15g of corn starch and add it into the reaction vessel, stir and heat, when the temperature rises Reflux occurs at 78°C, keep warm and return to room temperature after 100 minutes; filter with suction, and wash 4 times with 300ml of 95% ethanol to obtain pre-swelled starch in the form of particles;

[0043] Add the obtained pre-swelled starch into the reaction vessel, add 95ml 90% ethanol solution, 2g potassium hydroxide and 75ml propylene oxide, stir evenly and then heat, when the temperature rises to 68°C, there will be reflux phenomenon, keep the temperature for 100 minutes Back to room temperature; use 10% hydrochloric a...

Embodiment 3

[0045]The pre-swelling and hydroxypropylation reactions in this example were carried out in a reaction vessel equipped with an electric stirrer, a thermometer and a reflux condenser.

[0046] Measure 70ml of 90% ethanol solution and add in reaction vessel, get 0.5g (5% of starch weight) sodium hydroxide and add wherein and stir until completely dissolving; Take starch 10g and add in reaction vessel, stir and heat, when temperature rises to Reflux phenomenon occurs at 78°C, heat preservation and reflux for 110 minutes, then drop to room temperature; filter with suction, wash 4 times with 200ml of 95% ethanol to obtain pre-swelled starch in the form of particles.

[0047] The obtained pre-swelled starch is added in the reaction vessel, and 63ml of 90% ethanol solution, 2g of sodium hydroxide and 45ml of propylene oxide are added, heated evenly after stirring, when the temperature rises to 68°C, there is a reflux phenomenon, and the temperature is kept at reflux for 120 minutes. ...

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Abstract

The invention discloses a preparation method of hydroxypropyl starch. Before hydroxypropylation reaction, pre-swelling treatment is carried out on the starch, and polarity dispersant is adopted for the pre-swelling treatment and the hydroxypropylation reaction. The preparation method of the hydroxypropyl starch adopts the pre-swelling treatment so as to lead a supermolecular group in the starch to be limitedly expanded, the viscosity of a reaction system is moderate as the hydroxypropylation process has more reaction active centers, and the hydroxypropylation degree is effectively improved; the pre-swelling and the hydroxypropylation are both carried out under the condition of the constant pressure and the temperature not higher than 90 DEG C, the condition is mild, and the implementation is safe; the aqueous solution of common polar solvent such as methanol, alcohol or isopropanol is adopted in the reaction, the dispersibility of the starch and catalyst is good, the reaction rate is improved, the reaction time is shortened, and the reaction condition is reduced; in addition, the diluted acid can be directly adopted for neutralization after reaction, therefore, the operation is simpler, and the method is applicable to industrialized production.

Description

technical field [0001] The invention relates to a preparation method of modified starch, in particular to a preparation method of hydroxypropyl starch. Background technique [0002] Modified starch has developed rapidly in recent years due to its excellent properties and wide application. Hydroxypropyl starch is a kind of modified starch, which belongs to non-ionic etherified starch, has many excellent physical and chemical properties, and has been widely used in food, medicine, textile, daily chemicals and other fields. At present, the preparation methods of hydroxypropyl starch mainly include starch emulsion method, organic solvent method, dry method and microemulsion method, etc., and the methods that have realized industrial production include starch emulsion method and organic solvent method. [0003] The starch emulsion wet method is to put starch, 1,2-propylene oxide and other raw materials into water. Since water is used as the reaction medium, it is easy to cause e...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08B31/10
Inventor 鲁郑全陈宏伟袁兴龙鲁玺龙鲁东霞孙华琦朱靖
Owner 鲁郑全
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