A kind of preparation method of hydroxypropyl distarch phosphate

Abstract

The present invention relates to the technical field of starch, and discloses a preparation method of hydroxypropyl distarch phosphate. The present invention adds deionized water, sodium sulfate, sodium hydroxide into a reactor, adds starch after stirring, passes nitrogen, adds propylene oxide, and performs etherification reaction; then adds sodium trimetaphosphate, and the catalyst molecular sieve loads calcium chloride, performs cross-linking reaction, and obtains hydroxypropyl distarch phosphate. The molecular sieve loads calcium chloride catalyst of the present invention, which can more effectively catalyze the etherified starch and sodium trimetaphosphate to perform phosphate cross-linking reaction, and the obtained hydroxypropyl distarch phosphate has the advantages of low sedimentation volume and large cross-linking degree, and the cross-linked starch can still maintain a complete granular form after high-temperature gelatinization treatment, and the viscosity after high-speed shearing, the viscosity decrease range is small, the viscosity retention rate, and the shear resistance performance are very good.

Description

Technical Field

[0001] The invention relates to the technical field of starch, in particular to a method for preparing hydroxypropyl distarch phosphate. Background Art

[0002] Starch derivatives such as starch phosphate, acetylated starch, starch sulfate, cross-linked starch, etc. are widely used in the pharmaceutical industry, papermaking industry, water treatment, etc. Among them, hydroxypropyl distarch phosphate has the advantages of being odorless, tasteless, and having good water solubility. It has important applications in thickeners, food additives, etc., and the development of high-performance hydroxypropyl distarch phosphate is a research hotspot. Traditional hydroxypropyl distarch phosphate has problems such as low cross-linking degree, poor structural stability, and poor shear resistance. Patent CN116731212A discloses a method for preparing a waxy corn hydroxypropyl distarch phosphate with high cross-linking and low viscosity. The hydroxypropyl distarch phosphate obtained by using starch, sodium sulfate, sodium trimetaphosphate, propylene oxide, etc. as raw materials has the advantages of high cross-linking and low viscosity. Compared with the invention, the present invention uses molecular sieve loaded calcium chloride as a catalyst, and the obtained hydroxypropyl distarch phosphate has the advantages of higher cross-linking degree and better shear resistance. Summary of the invention

[0003] The technical problem solved by the invention is to provide a method for preparing hydroxypropyl distarch phosphate with a high cross-linking degree.

[0004] Technical solution: A method for preparing hydroxypropyl distarch phosphate, comprising:

[0005] (1) Add deionized water, sodium sulfate, and sodium hydroxide into a reactor, stir, add starch, introduce nitrogen, and add propylene oxide to carry out etherification reaction.

[0006] (2) Sodium trimetaphosphate and a catalyst molecular sieve loaded with calcium chloride are added to the reactor to carry out a cross-linking reaction. After cooling, a hydrochloric acid solution is added, and then water is added to dilute the mixture. After filtering, the filtrate is evaporated and concentrated until a precipitate is precipitated. The precipitate is cooled in an ice bath, filtered, washed with water, and dried to obtain hydroxypropyl distarch phosphate.

[0007] Preferably, the mass ratio of sodium sulfate, sodium hydroxide, starch, propylene oxide, sodium trimetaphosphate, and catalyst molecular sieve-loaded calcium chloride is (12-18): (0.6-1.3): 100: (8-14): (0.04-0.15): (0.006-0.02).

[0008] Preferably, the etherification reaction temperature is 40-55°C and the time is 6-10 hours.

[0009] Preferably, the cross-linking reaction temperature is 40-50° C. and the time is 12-24 hours.

[0010] Preferably, hydrochloric acid solution is added to adjust the pH of the reaction solution to 6.5-7.

[0011] Preferably, the preparation method of molecular sieve-loaded calcium chloride comprises: adding water and MCM-41 molecular sieve into a flask, dispersing by ultrasound, then adding an aqueous solution of calcium chloride, controlling the mass ratio of MCM-41 molecular sieve to calcium chloride to be 1:(2-5), stirring at 20-40° C. for 5-8 h, evaporating to remove water, and drying to obtain molecular sieve-loaded calcium chloride.

[0012] The technical effect of the present invention is as follows: the present invention uses MCM-41 molecular sieve as a catalyst carrier and calcium chloride as a catalytic active component to obtain a molecular sieve-loaded calcium chloride catalyst through an impregnation method.

[0013] The invention uses propylene oxide as an etherifying agent, sodium trimetaphosphate as a cross-linking agent, and adds a molecular sieve-loaded calcium chloride catalyst, which can more effectively catalyze the phosphate cross-linking reaction between etherified starch and sodium trimetaphosphate. The obtained hydroxypropyl distarch phosphate has the advantages of low sedimentation volume and high cross-linking degree. The cross-linked starch can still maintain a complete particle shape after high-temperature gelatinization treatment, has a small viscosity drop after high-speed shearing, and has good viscosity retention rate and anti-shearing performance. DETAILED DESCRIPTION

[0014] In order to understand the technical features and contents of the present invention in detail, the preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described in the embodiments, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described here.

[0015] Example 1

[0016] (1) Add 8 mL of water and 0.2 g of MCM-41 molecular sieve into a flask, disperse by ultrasound, then add 2 mL of an aqueous solution of 0.3 g of calcium chloride, stir at 20 °C for 8 h, evaporate to remove water, and dry to obtain molecular sieve-loaded calcium chloride.

[0017] (2) Add 130 mL of deionized water, 13 g of sodium sulfate, and 0.6 g of sodium hydroxide to the reactor, stir, add 100 g of corn starch, introduce nitrogen, add 8 g of propylene oxide, heat to 40°C, and carry out etherification reaction for 10 hours.

[0018] (3) Add 0.04 g of sodium trimetaphosphate and 6 mg of catalyst molecular sieve-loaded calcium chloride into the reactor, carry out a cross-linking reaction at 45° C. for 12 h, add hydrochloric acid solution to adjust the pH of the reaction solution to 7 after cooling, then add water to dilute, filter and evaporate the filtrate until a precipitate is precipitated, cool in an ice bath, filter and wash with water, and dry to obtain hydroxypropyl distarch phosphate.

[0019] Example 2

[0020] (1) Add 10 mL of water and 0.2 g of MCM-41 molecular sieve into a flask, disperse by ultrasonication, then add 4 mL of 1 g of calcium chloride aqueous solution, stir at 30 °C for 8 h, evaporate to remove water, and dry to obtain molecular sieve-loaded calcium chloride.

[0021] (2) Add 140 mL of deionized water, 12 g of sodium sulfate, and 0.8 g of sodium hydroxide to the reactor, stir, add 100 g of corn starch, pass nitrogen, add 10 g of propylene oxide, heat to 55 ° C, and carry out etherification reaction for 6 hours.

[0022] (3) Add 0.08 g of sodium trimetaphosphate and 10 mg of catalyst molecular sieve-loaded calcium chloride into the reactor, carry out a cross-linking reaction at 50° C. for 18 h, add hydrochloric acid solution to adjust the pH of the reaction solution to 6.5 after cooling, then add water to dilute, filter and evaporate and concentrate the filtrate until a precipitate is precipitated, cool in an ice bath, filter and wash with water, and dry to obtain hydroxypropyl distarch phosphate.

[0023] Example 3

[0024] (1) Add 5 mL of water and 0.2 g of MCM-41 molecular sieve into a flask, disperse by ultrasound, then add 2 mL of an aqueous solution of 0.1 g of calcium chloride, stir at 30 °C for 5 h, evaporate to remove water, and dry to obtain molecular sieve-loaded calcium chloride.

[0025] (2) Add 150 mL of deionized water, 16 g of sodium sulfate, and 1.1 g of sodium hydroxide to the reactor, stir, add 100 g of corn starch, introduce nitrogen, add 12 g of propylene oxide, heat to 45 ° C, and carry out etherification reaction for 10 hours.

[0026] (3) Add 0.11 g of sodium trimetaphosphate and 15 mg of catalyst molecular sieve-loaded calcium chloride into the reactor, carry out a cross-linking reaction at 50° C. for 18 h, add hydrochloric acid solution to adjust the pH of the reaction solution to 6.5 after cooling, then add water to dilute, filter and evaporate the filtrate until a precipitate is precipitated, cool in an ice bath, filter and wash with water, and dry to obtain hydroxypropyl distarch phosphate.

[0027] Example 4

[0028] (1) Add 8 mL of water and 0.2 g of MCM-41 molecular sieve into a flask, disperse by ultrasound, then add 3 mL of an aqueous solution of 0.7 g of calcium chloride, stir at 40 °C for 6 h, evaporate to remove water, and dry to obtain molecular sieve-loaded calcium chloride.

[0029] (2) Add 150 mL of deionized water, 18 g of sodium sulfate, and 1.3 g of sodium hydroxide to the reactor, stir, add 100 g of corn starch, pass nitrogen, add 14 g of propylene oxide, heat to 40°C, and carry out etherification reaction for 10 hours.

[0030] (3) Add 0.15 g of sodium trimetaphosphate and 20 mg of catalyst molecular sieve-loaded calcium chloride into the reactor, carry out a cross-linking reaction at 40° C. for 24 h, add hydrochloric acid solution to adjust the pH of the reaction solution to 7 after cooling, then add water to dilute, filter and evaporate the filtrate until a precipitate is precipitated, cool in an ice bath, filter and wash with water, and dry to obtain hydroxypropyl distarch phosphate.

[0031] Comparative Example 1

[0032] (1) Add 130 mL of deionized water, 13 g of sodium sulfate, and 0.6 g of sodium hydroxide to the reactor, stir, add 100 g of corn starch, introduce nitrogen, add 8 g of propylene oxide, heat to 40 ° C, and carry out etherification reaction for 10 hours.

[0033] (2) Add 0.04 g of sodium trimetaphosphate to the reactor, carry out a cross-linking reaction at 45° C. for 12 h, add hydrochloric acid solution to adjust the pH of the reaction solution to 7 after cooling, then add water to dilute, filter and evaporate the filtrate until a precipitate is precipitated, cool in an ice bath, filter and wash with water, and dry to obtain hydroxypropyl distarch phosphate.

[0034] Comparative Example 2

[0035] (1) Add 130 mL of deionized water, 13 g of sodium sulfate, and 0.6 g of sodium hydroxide to the reactor, stir, add 100 g of corn starch, introduce nitrogen, add 8 g of propylene oxide, heat to 40 ° C, and carry out etherification reaction for 10 hours.

[0036] (2) Add 0.04 g of sodium trimetaphosphate and 6 mg of MCM-41 molecular sieve to the reactor, carry out cross-linking reaction at 45° C. for 12 h, add hydrochloric acid solution to adjust the pH of the reaction solution to 7 after cooling, then add water to dilute, filter and evaporate the filtrate until a precipitate is precipitated, cool in an ice bath, filter and wash with water, and dry to obtain hydroxypropyl distarch phosphate.

[0037] Comparative Example 3

[0038] (1) Add 130 mL of deionized water, 13 g of sodium sulfate, and 0.6 g of sodium hydroxide to the reactor, stir, add 100 g of corn starch, introduce nitrogen, add 8 g of propylene oxide, heat to 40 ° C, and carry out etherification reaction for 10 hours.

[0039] (2) Add 0.04 g of sodium trimetaphosphate and 6 mg of calcium chloride to the reactor, carry out a cross-linking reaction at 45° C. for 12 h, add hydrochloric acid solution to adjust the pH of the reaction solution to 7 after cooling, then add water to dilute, filter and evaporate the filtrate until a precipitate is precipitated, cool in an ice bath, filter and wash with water, and dry to obtain hydroxypropyl distarch phosphate.

[0040] Add hydroxypropyl distarch phosphate to deionized water to make a solution with a mass fraction of 1-3%, heat to 95°C, stir for 10 minutes, cool to room temperature, take 100mL of the solution and pour it into a measuring cylinder, mix well and let it stand for 24 hours, and record the volume occupied by the sedimentation part. The cross-linking degree is linearly negatively correlated with the sedimentation volume. The smaller the sedimentation volume, the greater the cross-linking degree.

[0041] Table 1 Sedimentation volume and cross-linking degree test of hydroxypropyl distarch phosphate

[0042]

[0043] Add hydroxypropyl distarch phosphate to deionized water to make a 3% solution, heat to 95°C, stir and gelatinize for 20 minutes, cool to room temperature, perform high-speed shearing for 0.5 hours at a speed of 3000 r / min, test the viscosity with a viscometer, and then perform high-speed shearing for another 0.5 hours, and then test the viscosity again. The higher the viscosity retention rate, the better the shear resistance.

[0044] Table 2 Shear resistance test of hydroxypropyl distarch phosphate

[0045]

[0046] As can be seen from Table 1 and Table 2, Examples 1-4 use molecular sieve-loaded calcium chloride as a catalyst, which can more effectively catalyze the phosphate cross-linking reaction between etherified starch and sodium trimetaphosphate. The obtained hydroxypropyl distarch phosphate has the advantages of low sedimentation volume and high cross-linking degree. After high-temperature gelatinization treatment, the cross-linked starch can still maintain the complete particle morphology and structural stability. After high-speed shearing, the viscosity decreases less, and the viscosity retention rate and shear resistance are very good.

[0047] Comparative Example 1 did not add molecular sieve-loaded calcium chloride as a catalyst, and Comparative Example 2 only added MCM-41 molecular sieve. The resulting hydroxypropyl distarch phosphate had a large sedimentation volume, a low degree of crosslinking, a low shear viscosity retention rate, and poor shear resistance.

[0048] In Comparative Example 3, calcium chloride is used as a catalyst, and the sedimentation volume of the obtained hydroxypropyl distarch phosphate is higher than that of the embodiments, the cross-linking degree is lower, the shear viscosity retention rate is lower, and the shear resistance is poor.

[0049] The above describes some embodiments of the present invention, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for preparing hydroxypropyl distarch phosphate, characterized in that: The preparation method comprises: (1) adding deionized water, sodium sulfate, and sodium hydroxide into a reaction kettle, adding starch after stirring, introducing nitrogen, and adding propylene oxide to carry out etherification reaction; (2) adding sodium trimetaphosphate and a catalyst molecular sieve loaded with calcium chloride to the reactor to carry out a crosslinking reaction, adding a hydrochloric acid solution after cooling, then adding water to dilute, filtering, evaporating and concentrating the filtrate until a precipitate is precipitated, cooling in an ice bath, filtering, washing with water, and drying to obtain hydroxypropyl distarch phosphate; The preparation method of molecular sieve-loaded calcium chloride comprises: adding water and MCM-41 molecular sieve into a flask, dispersing by ultrasonication, then adding an aqueous solution of calcium chloride, stirring, evaporating to remove water, and drying to obtain molecular sieve-loaded calcium chloride; The mass ratio of the MCM-41 molecular sieve to calcium chloride is 1:(2-5).

2. The method for preparing hydroxypropyl distarch phosphate according to claim 1, characterized in that: The mass ratio of the sodium sulfate, sodium hydroxide, starch, propylene oxide, sodium trimetaphosphate, and catalyst molecular sieve-loaded calcium chloride is (12-18):(0.6-1.3):100:(8-14):(0.04-0.15):(0.006-0.02).

3. The method for preparing hydroxypropyl distarch phosphate according to claim 1, characterized in that: The temperature of the etherification reaction is 40-55° C. and the time is 6-10 hours.

4. The method for preparing hydroxypropyl distarch phosphate according to claim 1, characterized in that: The temperature of the cross-linking reaction is 40-50° C. and the time is 12-24 hours.

5. The method for preparing hydroxypropyl distarch phosphate according to claim 1, characterized in that: The addition of the hydrochloric acid solution is used to adjust the pH of the reaction solution to 6.5-7.

6. The method for preparing hydroxypropyl distarch phosphate according to claim 1, characterized in that: In the preparation method of molecular sieve loaded calcium chloride, the stirring temperature is 20-40° C. and the stirring time is 5-8 hours.

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