CN115850732B - Dry high temperature resistant hydrogel and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of materials, and particularly relates to a dry high-temperature-resistant hydrogel and a preparation method thereof. The invention adopts a mode of physically crosslinking the water-soluble thickening agent, the chelating agent and the crosslinking agent and is assisted by the compound, thereby enhancing the intermolecular interaction force, particularly the hydrogen bonding action, in the hydrogel so as to improve the stability of the hydrogel structure and further realize the purpose of high temperature resistance. The dry high-temperature-resistant hydrogel has the advantages of simple preparation process, readily available raw materials and low cost, and can realize mass production. The hydrogel prepared by the method has higher thermal stability, can keep stable structure after being boiled for more than 6 hours at 90 ℃, has good water absorption rate, moderate hardness and strong gel feel, and can be better applied to the fields of medical dressing, daily chemicals and the like.

Description

Dry high temperature resistant hydrogel and preparation method thereof

Technical Field

The invention relates to the field of high polymer materials, in particular to a dry high temperature resistant hydrogel and a preparation method thereof.

Background

The hydrogel takes water as a dispersion medium, has a high molecular network system, is soft in property, can keep a certain shape, can absorb a large amount of water, can furthest solve the defects of small adsorption capacity, insufficient water retention capacity, poor skin adhesion and the like, has a great application prospect, and is widely focused by scientists, engineers and business people in recent decades. At present, the application field of the hydrogel has been expanded to the high and new technical fields of super absorbent materials, food industry, medical dressing, cornea contact lens, medicine slow-release matrix, chemical valve, soft tissue filling of human body, mask matrix material and the like. Particularly, the hydrophilic mask prepared from hydrogel at present is popular with consumers due to the advantages of good transparency, full naturalness, high safety, rich water content and the like.

The existing hydrogel in the market mainly takes carrageenan polysaccharide substances as main materials, and potassium salt, calcium salt and the like are used as auxiliary materials, and the hydrogel is obtained through a physical crosslinking mode. Polysaccharide substances are easy to hydrolyze, hydrogel exists in a wet state in practical products, and the hydrolysis of the hydrogel is easier to be promoted when the temperature of a container is high in summer or in a truck carrying process. Patent CN201410226170.1 mentions a high temperature stable hydrogel mask patch which can only be kept stable below 55 ℃, and the raw material composition is relatively complex and the cost is high.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide the dry high temperature resistant hydrogel which has low cost, simple process, high temperature resistance, good water absorption multiplying power, moderate hardness and strong gel feel and the preparation method thereof.

In order to achieve the aim of the invention, the invention adopts the following technical scheme:

in one aspect, a method for preparing a dry high temperature resistant hydrogel comprises the steps of:

(1) Adding a water-soluble thickener, a chelating agent and a crosslinking agent into a beaker, adding an organic solvent, and stirring to obtain a mixture A;

(2) Adding acid or an aqueous solution of the acid into the mixture A, and stirring to obtain a mixture B;

(3) Adding the compound into the mixture B, and stirring to obtain a mixture C;

(4) Vacuum defoamation, discharging and coating are carried out on the mixture C, and then drying is carried out, thus obtaining dry high temperature resistant hydrogel;

Preferably, the water-soluble thickener is an organic synthetic water-soluble polymer, more preferably, the water-soluble thickener is sodium polyacrylate, and even more preferably, the water-soluble thickener is sodium polyacrylate.

Preferably, the chelating agent is one or more of disodium EDTA, tetrasodium EDTA, dipotassium EDTA.

Preferably, the cross-linking agent is organic or inorganic aluminum salt, and more preferably, the cross-linking agent is one or more of aluminum chloride, aluminum glycollate, aluminum sulfate, alum, aluminum hydroxide, aluminum silicate, aluminum nitrate and aluminum oxide.

Preferably, the organic solvent is one or more of glycerol, polyethylene glycol-200, polyethylene glycol-400, polyethylene glycol-600, polyglycerol-10, methoxypolyethylene glycol 1000 methacrylate, polyethylene oxide polypropylene oxide monobutyl ether, polyoxyethylene polyoxypropylene ether, polyethylene glycol and propylene glycol copolymer, and ethylhexyl palmitate.

Preferably, the acid or the aqueous acid solution is one or more of tartaric acid aqueous solution, citric acid aqueous solution, oxalic acid aqueous solution, lactic acid aqueous solution, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid and oxalic acid.

Preferably, the compound is one or more of polyvinyl alcohol, polyvinylpyrrolidone, sodium carboxymethyl cellulose, hydroxyethyl cellulose, carob bean gum, kaolin, bentonite, polyurethane emulsion, printing paste, glycerol polyacrylate, rosin glyceride, acrylic polymer emulsion and acrylic copolymer emulsion.

Preferably, the substrate used for coating in the step (4) is any one of a nonwoven fabric, a POPP film, and a PET film.

Preferably, the mass ratio of the water-soluble thickener, the chelating agent and the cross-linking agent is 40-2200:1:2-2100.

Preferably, the mass ratio of the organic solvent to the water-soluble thickener is 2-100:1.

Further preferably, the mass ratio of the organic solvent to the water-soluble thickener is 3-5:1.

Preferably, the mass ratio of the acid or the aqueous solution of the acid to the water-soluble thickener is 1:1-30.

Further preferably, the mass ratio of the acid or the aqueous solution of the acid to the water-soluble thickener is 1:3-12.

Preferably, the mass ratio of the compound to the water-soluble thickener is 1:0.1-10.

Further preferably, the mass ratio of the compound to the water-soluble thickener is 1:0.8-2.

Preferably, in the step (4), the drying temperature is 40-180 ℃ and the drying time is 1-120 min.

Further preferably, in the step (4), the drying temperature is 50-145 ℃ and the drying time is 2-60 min.

On the other hand, the invention provides the dry high temperature resistant hydrogel prepared by the preparation method and the application of the dry high temperature resistant hydrogel prepared by the preparation method as a medical dressing matrix material, a mask matrix material or a water absorbing material.

The dry high-temperature-resistant hydrogel is prepared by adopting the specific preparation method, and the technological parameters and the reaction conditions are contained in the whole and matched with each other, so that better effects can be obtained in the aspects of improving the structural stability and the water absorbability of the hydrogel.

According to the invention, sodium polyacrylate is used as a thickening agent, EDTA disodium or EDTA tetrasodium is added as a chelating agent, aluminum salt or aluminum oxide/hydroxide is used as a crosslinking agent, physical crosslinking is carried out under specific parameter conditions, and a compound with a thickening effect is added, so that the obtained crosslinked product has stronger intermolecular acting force, particularly stronger hydrogen bonding effect, and the obtained hydrogel has better high temperature resistance.

Compared with the prior art, the invention has the following beneficial effects:

the invention adopts a mode of physically crosslinking the water-soluble thickening agent, the chelating agent and the crosslinking agent, and is assisted with the compound, thereby improving the stability of the hydrogel structure.

The hydrogel prepared by the method has higher thermal stability and can keep stable form and property at a high temperature of 90 ℃.

Furthermore, the hydrogel prepared by the method has higher thermal stability in a wet state, and can be quickly dried under a high-temperature condition, so that the process time is greatly shortened, and the production cost is reduced.

Furthermore, the method selects the relatively stable sodium polyacrylate as the main raw material for preparing the dry high-temperature-resistant hydrogel, and the hydrogel can be obtained through four steps, so that the raw material is easy to obtain, the cost is low, the preparation process is simple, and the mass production can be realized.

Further, the hydrogel prepared by the method disclosed by the invention is moderate in softness and hardness and strong in gel feel.

Furthermore, the hydrogel prepared by the method provided by the invention has good water absorption rate, and can be better applied to the fields of medicine, daily chemicals and the like.

Detailed Description

The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.

The raw materials adopted in the embodiment and the comparative example are all commercially available, wherein the manufacturer of the sodium polyacrylate is 3D5 of the type of the biological technology Co., ltd. In the new Congress of Jiangmen, and the mesh number is 90 mesh.

Example 1

The embodiment provides a high temperature resistant hydrogel, which is prepared by the following method:

(1) 9.0g of sodium polyacrylate, 0.2g of EDTA disodium, 0.15g of aluminum sulfate and 0.55g of alum are weighed into a beaker, and 30.0g of glycerin is added for pre-dispersion. Stirring uniformly for standby.

(2) Weighing 0.8g of tartaric acid in a beaker, adding 60.0g of pure water, stirring uniformly, then adding the mixture into the beaker in the step (1), and stirring fully to uniformly mix the mixture.

(3) 7.0G of kaolin complex is weighed out, 500 mesh. Adding 30g of water into a beaker, stirring uniformly, then adding the mixture into the beaker in the step (2), and stirring fully to uniformly mix the mixture.

(4) And (3) carrying out vacuum defoaming on the colloid obtained in the step (3), coating the defoamed colloid on a PET film, and drying for 5min at 100 ℃ by using an oven to obtain the high-temperature-resistant hydrogel in a dehydrated state.

And (3) carrying out destructive experiments on the product, adding 200ml of tap water into a water bath kettle to keep the temperature to 65 ℃, taking 1g of the hydrogel prepared in the step (3), wrapping the hydrogel by using a gauze, and then heating the hydrogel in the water bath kettle at 65 ℃ for 50min, wherein the hydrogel is not dissolved and crushed, the whole gel is kept intact, and the hydrogel before and after heating has moderate touch and hardness and strong gel feel.

Example 2

A high temperature resistant hydrogel is prepared by the following method:

(1) Weighing 5.5g of sodium polyacrylate, 0.1g of EDTA tetrasodium, 1.4g of aluminum hydroxide in a beaker, adding 25.0g of polyglycerol-10, and uniformly stirring for later use.

(2) Weighing 1.5g of citric acid in a beaker, adding 60g of pure water, stirring uniformly, then adding the mixture into the beaker in the step (1), and stirring fully to uniformly.

(3) Weighing 1.5g of polyvinylpyrrolidone in a beaker, adding 40g of pure water and 5g of polyurethane emulsion, stirring uniformly, then adding the mixture into the beaker in the step (2), and stirring fully to uniformly mix the mixture.

(4) And (3) carrying out vacuum defoaming on the colloid obtained in the step (3), coating the defoamed colloid on a PET film, and drying the PET film for 8min at 95 ℃ by using an oven to obtain the high-temperature-resistant hydrogel in a dehydrated state.

And (3) carrying out destructive experiments on the product, adding 200ml of tap water into a water bath kettle to keep the temperature to 75 ℃, taking 1g of the hydrogel prepared in the step (3), wrapping the hydrogel by using a gauze, and then heating the hydrogel in the water bath kettle at 75 ℃ for 30min, wherein the hydrogel is not dissolved and crushed, the whole gel is kept intact, and the hydrogel before and after heating has moderate touch and hardness and strong gel feel.

Example 3

A high temperature resistant hydrogel is prepared by the following method:

(1) Weighing 5.0g of sodium polyacrylate, 0.1g of EDTA disodium, 1.2g of aluminum chloride and 0.8g of aluminum oxide into a beaker, adding 20.0g of polyethylene glycol-400, and uniformly stirring for later use.

(2) 12Ml of 5% hydrochloric acid solution was measured and added to the beaker of step (1), followed by stirring thoroughly to make it uniform.

(3) Weighing 2.5g of sodium carboxymethylcellulose in a beaker, adding 80g of pure water, stirring uniformly, then adding the sodium carboxymethylcellulose in the beaker in the step (2), and stirring fully to uniformly mix the sodium carboxymethylcellulose and the pure water.

(4) And (3) carrying out vacuum defoaming on the colloid obtained in the step (3), coating the defoamed colloid on a PET film, and drying for 3min at 120 ℃ by using an oven to obtain the high-temperature-resistant hydrogel in a dehydrated state.

And (3) carrying out destructive experiments on the product, adding 200ml of tap water into a water bath kettle to keep the temperature to 90 ℃, taking 1g of hydrogel prepared in the step (3), wrapping the hydrogel by using a gauze, and then heating the hydrogel in the water bath kettle at 90 ℃ for 70min, wherein the hydrogel is not dissolved and crushed, the whole gel is kept intact, and the hydrogel before and after heating has moderate touch and hardness and strong gel feel.

Example 4

The hydrogels obtained in examples 1 to 3 were compared with the thermal stability of conventional polysaccharide hydrogels (a water silk membrane purchased from bead sea silk new materials, intelligent manufacturing technology Co., ltd.) by cutting 2g of wet hydrogel and 0.5g of dry hydrogel, wrapping with gauze, boiling in a water bath at 65℃and 90℃for 6 hours, adding 50 times of pure water at 25℃and standing for 6 hours, and observing the dissolution of the hydrogels to determine the thermal stability of the hydrogels, wherein the wet hydrogel is obtained by taking out 0.5g of dry hydrogel after absorbing water in 100g of deionized water for 2 hours, and the test results are shown in the following table:

From the table above, the hydrogel prepared by the method provided by the invention has better thermal stability at 65-90 ℃.

The applicant states that the present invention is illustrated by the above examples as a dry high temperature resistant hydrogel and a method of preparing the same, but the present invention is not limited to the above examples, i.e. it is not meant that the present invention must be practiced in dependence upon the above examples. It should be apparent to those skilled in the art that any modification of the present invention, equivalent substitution of raw materials for the product of the present invention, addition of auxiliary components, selection of specific modes, etc., falls within the scope of the present invention and the scope of disclosure.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention. In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Claims (4)

1. The preparation method of the dry high temperature resistant hydrogel is characterized by comprising the following steps of:

(1) Weighing 5.5g of sodium polyacrylate, 0.1g of EDTA tetrasodium, 1.4g of aluminum hydroxide in a beaker, adding 25.0g of polyglycerol-10, and uniformly stirring for later use;

(2) Weighing 1.5g of citric acid in a beaker, adding 60g of pure water, uniformly stirring, then adding the mixture into the beaker in the step (1), and fully stirring to uniformly obtain the mixture;

(3) Weighing 1.5g of polyvinylpyrrolidone in a beaker, adding 40g of pure water and 5g of polyurethane emulsion, uniformly stirring, then adding the mixture into the beaker in the step (2), and fully stirring to uniformly mix the mixture;

(4) And (3) carrying out vacuum defoaming on the colloid obtained in the step (3), coating the defoamed colloid on a PET film, and drying the PET film for 8min at 95 ℃ by using an oven to obtain the high-temperature-resistant hydrogel in a dehydrated state.

2. The preparation method of the dry high temperature resistant hydrogel is characterized by comprising the following steps of:

(1) Weighing 5.0g of sodium polyacrylate, 0.1g of EDTA disodium, 1.2g of aluminum chloride and 0.8g of aluminum oxide in a beaker, adding 20.0g of polyethylene glycol-400, and uniformly stirring for later use;

(2) Weighing 12ml of 5% hydrochloric acid solution, adding into the beaker in the step (1), and fully stirring to be uniform;

(3) Weighing 2.5g of sodium carboxymethylcellulose in a beaker, adding 80g of pure water, stirring uniformly, then adding the sodium carboxymethylcellulose in the beaker in the step (2), and fully stirring to uniformly mix the sodium carboxymethylcellulose;

(4) And (3) carrying out vacuum defoaming on the colloid obtained in the step (3), coating the defoamed colloid on a PET film, and drying for 3min at 120 ℃ by using an oven to obtain the high-temperature-resistant hydrogel in a dehydrated state.

3. A dry high temperature resistant hydrogel prepared by the method of any one of claims 1-2.

4. Use of the dry high temperature resistant hydrogel of claim 3 in the preparation of a medical dressing matrix material, a mask matrix material or a water absorbing material.