CN114437240B

CN114437240B - Preparation method of hydrophobic starch

Info

Publication number: CN114437240B
Application number: CN202011233607.6A
Authority: CN
Inventors: 张雷达; 赵伟; 梁金玲; 朱俊; 齐丹萍; 王健
Original assignee: Shandong Fuyang Biotechnology Co ltd
Current assignee: Shandong Fuyang Biotechnology Co ltd
Priority date: 2020-11-06
Filing date: 2020-11-06
Publication date: 2023-04-28
Anticipated expiration: 2040-11-06
Also published as: CN114437240A

Abstract

The invention discloses a preparation method of hydrophobic starch, and belongs to the technical field of starch denaturation. The invention discloses a preparation method of hydrophobic starch, which comprises the steps of preparing starch into starch milk, adding maleic anhydride for esterification reaction, neutralizing with acid, filtering, washing, drying and crushing to obtain starch ester; and adding soybean oil and an initiator into the obtained starch ester, and reacting to obtain the hydrophobic starch. The starch prepared by the invention has the advantages of good hydrophobicity, wide raw material sources, low production cost and the like, can improve the compatibility with other hydrophobic materials, and is widely applied to the fields of product inner packaging, buffering foam materials and the like.

Description

Preparation method of hydrophobic starch

Technical Field

The invention relates to the technical field of starch denaturation, in particular to a preparation method of hydrophobic starch.

Background

Plastics and their articles are the most common hydrophobic materials. However, the traditional plastic materials are usually made of petroleum refined products, and the characteristics of toxic gases generated by plastic combustion, incapability of natural degradation and the like seriously pollute the environment, so that the development of hydrophobic biodegradable materials by taking natural polymers as raw materials becomes a research hot spot.

The starch is used as a natural renewable resource, has wide sources, low cost and biodegradability, and contains a large number of hydroxyl groups in the molecule, so that chemical reactions such as esterification, etherification, grafting, crosslinking and the like can be carried out. The hydrophobicity of the starch molecule can be obviously improved by introducing a lipophilic group on the starch skeleton. The vegetable oil is also a natural renewable resource, contains rich functional groups, can be modified conveniently, and is an ideal substitute for petroleum.

Currently, the hydrophobic modification of starch is mainly the introduction of long-chain alkyl, alkyl fatty acid or alkenyl succinic acid groups on the starch molecular chain. On the basis of the report that the hydrophobic starch is prepared by reacting starch with vegetable oil, the novel hydrophobic starch with richer types and superior performance is researched on the basis of the prior art, and has positive significance for the development and scientific progress of human society.

Therefore, providing a method for preparing hydrophobic starch is a problem that needs to be solved by those skilled in the art.

Disclosure of Invention

In view of the above, the present invention provides a method for preparing hydrophobic starch, by which the hydrophobic starch is prepared, not only energy consumption can be reduced, but also environmental pollution can be reduced.

In order to achieve the above purpose, the present invention adopts the following technical scheme:

a preparation method of hydrophobic starch comprises the following specific steps:

(1) Preparing starch into starch milk, and adding 3% sodium hydroxide to adjust the pH to 8.0-9.0; adding maleic anhydride, stirring uniformly, and reacting for 2-10 h at 20-45 ℃; neutralizing with 3% hydrochloric acid to pH 6.5-7.0, filtering, washing, oven drying, and pulverizing to obtain maleic acid starch ester; the addition amount of the maleic anhydride is 1-10% of the mass of the starch;

(2) Preparing the maleic acid starch ester prepared in the step (1) into maleic acid starch milk, adding soybean oil, stirring and mixing for 10min, adding an initiator, reacting for 2-10 h at 100-170 ℃, and filtering, washing, drying and crushing after the reaction is finished to obtain hydrophobic starch; the addition amount of the soybean oil is 30% -50% of the mass of the starch maleate; the addition amount of the initiator is 1-5% of the mass of the starch maleate.

Further, the starch in the step (1) is at least one of corn starch, wheat starch, tapioca starch, potato starch and rice starch.

Further, the concentration of the starch milk in the step (1) is 20% -40%.

Further, the concentration of the maleic acid starch milk in the step (2) is 20% -40%.

Further, the initiator in the step (2) is at least one of benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide and cumene hydroperoxide.

Further, the drying in the step (1) and the step (2) is carried out for 4-6 hours at the temperature of 101-105 ℃.

Compared with the prior art, the invention discloses a preparation method of hydrophobic starch, which takes starch and soybean oil as main raw materials, and has the advantages of natural raw materials, wide sources and lower production cost; the prepared hydrophobic starch is nontoxic and harmless, degradable and environment-friendly; the starch is reacted with maleic anhydride to generate maleic acid starch ester, unsaturated double bonds are introduced into starch molecules, then the unsaturated double bonds react with soybean oil, and the soybean oil is connected to a starch chain to prepare hydrophobic starch, so that a new way is opened up for the efficient utilization of starch, and the added value of starch is improved; the preparation method provided by the invention is environment-friendly and efficient, is simple and convenient to operate, can improve the compatibility with other hydrophobic materials, and is widely applied to the fields of product inner packaging, buffering foam materials and the like.

Detailed Description

The following description of the technical solutions in the embodiments of the present invention will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

(1) Preparing corn starch into 40% starch milk, and adding 3% sodium hydroxide to adjust pH to 9.0; adding maleic anhydride accounting for 3% of the mass of the corn starch, uniformly stirring, and reacting for 2 hours at 40 ℃; neutralizing with 3% hydrochloric acid to pH7.0, filtering, washing, oven drying at 105deg.C for 4 hr, and pulverizing to obtain maleic acid starch ester;

(2) Preparing the starch maleate prepared in the step (1) into 40% starch maleate milk, adding soybean oil accounting for 40% of the mass of the starch maleate, stirring and mixing for 10min, adding benzoyl peroxide accounting for 3% of the mass of the starch maleate, reacting for 6h at 120 ℃, filtering, washing, drying for 4h at 105 ℃ after the reaction is finished, and crushing to obtain the hydrophobic starch.

Example 2

(1) Preparing tapioca starch into 25% starch milk, and adding 3% sodium hydroxide to adjust pH to 8.5; adding maleic anhydride accounting for 1% of the mass of the tapioca starch, uniformly stirring, and reacting for 4 hours at 35 ℃; neutralizing with 3% hydrochloric acid to pH6.5, filtering, washing, oven drying at 105deg.C for 5 hr, and pulverizing to obtain maleic acid starch ester;

(2) Preparing 30% of maleic acid starch milk from the maleic acid starch ester prepared in the step (1), adding soybean oil accounting for 30% of the mass of the maleic acid starch ester, and stirring and mixing for 10min; adding methyl ethyl ketone peroxide accounting for 3% of the mass of the starch maleate, reacting for 4 hours at 150 ℃, filtering, washing, drying at 105 ℃ for 4.5 hours after the reaction is finished, and crushing to obtain the hydrophobic starch.

Example 3

(1) Preparing wheat starch into 40% starch milk, and adding 3% sodium hydroxide to adjust pH to 8.5; adding maleic anhydride accounting for 5% of the mass of the wheat starch, uniformly stirring, and reacting for 10 hours at 30 ℃; neutralizing with 3% hydrochloric acid to pH7.0, filtering, washing, oven drying at 101 deg.C for 6 hr, and pulverizing to obtain maleic acid starch ester;

(2) Preparing 30% of maleic acid starch milk from the maleic acid starch ester prepared in the step (1), adding soybean oil accounting for 50% of the mass of the maleic acid starch ester, and stirring and mixing for 10min; adding benzoyl peroxide accounting for 3% of the mass of the starch maleate, reacting for 6 hours at 120 ℃, filtering, washing, drying for 5 hours at 105 ℃ after the reaction is finished, and crushing to obtain the hydrophobic starch.

Example 4

(1) Preparing potato starch into 35% starch milk, and adding 3% sodium hydroxide to adjust pH to 8.0; adding maleic anhydride accounting for 2% of the mass of potato starch, stirring uniformly, and reacting for 3 hours at 45 ℃; neutralizing with 3% hydrochloric acid to pH6.5, filtering, washing, oven drying at 103 deg.C for 5.5 hr, and pulverizing to obtain maleic acid starch ester;

(2) Preparing the starch maleate prepared in the step (1) into 35% starch maleate milk, adding soybean oil accounting for 35% of the mass of the starch maleate, and stirring and mixing for 10min; adding cumene hydroperoxide with the mass of 1% of that of the starch maleate, reacting for 10 hours at 100 ℃, filtering, washing, drying for 4 hours at 105 ℃ after the reaction is finished, and crushing to obtain the hydrophobic starch.

Example 5

(1) Preparing rice starch into 35% starch milk, and adding 3% sodium hydroxide to adjust pH to 8.5; adding maleic anhydride accounting for 10% of the mass of the rice starch, uniformly stirring, and reacting for 6 hours at 20 ℃; neutralizing with 3% hydrochloric acid to pH6.5, filtering, washing, oven drying at 101 deg.C for 6 hr, and pulverizing to obtain maleic acid starch ester;

(2) Preparing starch maleate prepared in the step (1) into 20% starch maleate milk, adding soybean oil accounting for 50% of the mass of the starch maleate, and stirring and mixing for 10min; adding dicumyl peroxide accounting for 2% of the mass of the starch maleate and 3% of methyl ethyl ketone peroxide, reacting for 2 hours at 170 ℃, filtering, washing, drying at 105 ℃ for 4.5 hours after the reaction is finished, and crushing to obtain the hydrophobic starch.

Comparative example 1

Common cornstarch was used as a comparative example.

Comparative example 2

Common tapioca starch was used as a comparative example.

The hydrophobic starches prepared in examples 1 to 5 of the present invention and the ordinary starches of comparative examples 1 to 2 were respectively mixed with polylactic acid and extruded, and then measured, and the measurement results are shown in Table 1.

Measurement of hydrophobicity Property

Starch-based polylactic acid granules (dry weight) with uniform size (20 grains/g) are taken, soaked in deionized water at 20 ℃ for 30min, taken out, and weighed (wet weight) after the surface moisture is absorbed.

Water absorption = (wet weight-dry weight)/dry weight x 100%

TABLE 1

	Example 1	Example 2	Example 3	Example 4	Example 5	Comparative example 1	Comparative example 2
								Water absorption/%	13.6	12.5	14.7	12.6	12.3	31.8	30.2

As can be seen from the data in Table 1, the hydrophobic starches prepared in examples 1-5 of the present invention have low water absorption and good hydrophobicity, solve the problem that conventional starches are sensitive to humidity and easily absorb water, and can be widely applied to the fields of product inner packaging, buffer foam materials and the like.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The preparation method of the hydrophobic starch is characterized by comprising the following specific steps:

(1) Preparing starch into starch milk, and adding 3% sodium hydroxide to adjust the pH to 8.0-9.0; adding maleic anhydride, stirring uniformly, and reacting for 2-10 h at 20-45 ℃; neutralizing with 3% hydrochloric acid to pH 6.5-7.0, filtering, washing, drying, and pulverizing to obtain maleic acid starch ester; the addition amount of the maleic anhydride is 1-10% of the mass of the starch;

(2) Preparing the maleic acid starch ester prepared in the step (1) into maleic acid starch milk, adding soybean oil, stirring and mixing for 10min, adding an initiator, reacting for 2-10 h at 100-170 ℃, and filtering, washing, drying and crushing after the reaction is finished to obtain hydrophobic starch; the addition amount of the soybean oil is 30% -50% of the mass of the starch maleate; the addition amount of the initiator is 1-5% of the mass of the starch maleate;

the starch in the step (1) is at least one of corn starch, wheat starch, tapioca starch, potato starch and rice starch;

the concentration of the starch milk in the step (1) is 20% -40%;

the concentration of the maleic acid starch emulsion in the step (2) is 20% -40%;

the initiator in the step (2) is at least one of benzoyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide and cumene hydroperoxide;

and (3) drying in the step (1) and the step (2) at the temperature of 101-105 ℃ for 4-6 h.