CN100406499C - Nanocomposite hydrogel and preparation method thereof - Google Patents

Abstract

The invention discloses a nanometer compound aquagel and preparing method, which comprises the following steps: polymerizing the prepolymer liquid at 25-35 deg.c for 20-30 h to obtain the product. The monomer is selected from acrylamide. The crosslink is selected from hectorite of modified sodium pyrophosphate. The general formula of chemical structure is Mg5.34Li0.66Si8O20 (OH) 4Na0.66.

Description

Nanocomposite hydrogel and preparation method thereof

technical field

The invention relates to a preparation method of nanocomposite hydrogel.

Background of the invention

Polymer hydrogel is a polymer with a three-dimensional network structure that can absorb a large amount of water and swell, and is generally formed by cross-linking hydrophilic homopolymers or copolymers. Hydrogels are insoluble in water, but swell in water.

In the past few decades, there has been a surge of research on environmentally sensitive and physiologically sensitive hydrogels, and the typical response of sensitive hydrogels is the change of hydrogel volume. This volume change is discontinuous, and using this stimuli-responsive property, hydrogels have been applied in the following aspects: in the chemical industry for separation; in medicine for the controlled release of drugs; in the mechanical industry Used to make memory element switches, sensors, etc.

However, because polymer gels are generally formed by cross-linking polymers, the cross-linking density is not uniform, the stress is easily concentrated on the short chains, causing the system to break under lower stress, and the mechanical properties are poor, so it is rarely used in mechanical devices. .

In recent years, three novel methods for the synthesis of high-strength hydrogels have emerged: topological (TP) gels, double network (DN) gels, and nanoscale (NC) gels. Compared with the other two gel synthesis methods, the nanogel forms a new structure through in-situ free radical polymerization, the synthesis process is simple, and the mechanical properties of the gel are greatly improved.

The nanogel reported by people such as Haraguchi in Japan is to polymerize iso-propylacrylamide and polyN,N-dimethylacrylamide as raw materials, and utilize clay (hectorite modified by pyrophosphoric acid) as a crosslinking agent The two polymers are polymerized, and the research shows that the strength of the two clay-crosslinked polymers increases with the increase of the clay content, and obtains a good elongation, which can reach 1000%, but the two materials are in The poor resilience after large deformation also limits the development of hydrogels in applications.

Polyacrylamide is colorless, transparent, soft and elastic, physiologically non-irritating, without complex physiological reactions and systemic poisoning, has good tissue compatibility and biological inertia, and is suitable for surgical expansion Space viscoelastics have been used in medicine as implants in the body. Liu et al. used clay as a polyacrylamide cross-linking agent, which has high resilience, but poor water absorption.

Contents of the invention

The problem to be solved by the present invention is to disclose a nano hydrogel and its preparation method, so as to overcome the above-mentioned defects in the prior art.

The preparation method of nanometer hydrogel of the present invention, comprises the steps:

(1) Initiate free radical polymerization of the pre-polymerization solution at 25-35°C, the polymerization time is 20-30h, and then keep the polymerization product at a temperature of 35-80°C for 5-20 days to obtain the said nanocomposite hydrogels;

Component and weight content of said pre-polymerization liquid, based on the weight of water, include:

Monomer accounts for 10-20% of water weight

Crosslinking agent 5-10% by weight of water

Initiator accounts for 0.1-0.2% of water weight

Catalyst 0.1-0.2% by weight of water

Said monomer is selected from acrylamide;

Said cross-linking agent is selected from laponite modified by sodium pyrophosphate, and its general chemical structure is: Mg _5.34 Li _0.66 Si ₈ O ₂₀ (OH) ₄ Na _0.66 , commonly known as "clay", which can be commercially available product;

Said initiator is selected from one of potassium persulfate, ammonium persulfate or azobisisobutyronitrile;

Said catalyst is selected from one of N, N, N', N'-tetramethylethylenediamine, triethanolamine or sodium persulfate;

According to the preferred method of the present invention, the cross-linking agent is added into water to infiltrate and peel off to form a cross-linking agent sheet with a thickness of about 1-2nm and a diameter of about 20-30nm, and then add other raw materials into the cross-linking agent aqueous solution reaction.

The nano hydrogel obtained by the above method is obtained by in-situ radical polymerization with acrylamide as a monomer and heat treatment. The method has simple process and high polymerization efficiency, and the obtained polyacrylamide not only has high strength, high elongation, high rebound elasticity but also has high water absorption.

Detailed ways

Example 1

Weigh 1.5 grams of clay and dissolve it in 28 grams of deionized water solution, put it in a 150ml beaker and stir for 2 hours. After the clay is completely dissolved in the water solution to form a uniform and stable solution, weigh 3 grams of acrylamide, add it to the beaker and continue stirring. At the same time, 0.03 grams of potassium persulfate was weighed and dissolved in 2 grams of deionized water, and 0.024 grams of catalyst TEMED was added to the beaker at the same time, and stirred evenly to form a prepolymer solution.

Nitrogen gas was bubbled into the prepolymer solution for 30 minutes to remove residual oxygen in the solution. Then inject the solution into a glass tube with a length of 60 mm and a diameter of 5 mm, keep at 30° C., and react for 24 hours. The preliminarily obtained gel was placed in a thermal incubator at 40° C. and kept warm for 5 days to obtain a nanogel.

The mechanical property of composite gel and the water-absorbing property test adopt in 2006 macromolecule letter 27 volumes, and the method mentioned in the report of people such as Zhu is detected, and its result is as follows:

Strength: 111kPa

Elongation: 3374%

Resilience: 90-95%

Water absorption: 2425 times.

Example 2

Weigh 1.5 grams of clay and dissolve it in 28 grams of deionized water solution, place it in a 150ml beaker and stir for 2 hours. After the clay is completely dissolved in the water solution to form a uniform and stable solution, weigh 4.5 grams of AAm and add it to the beaker to continue stirring. At the same time, 0.03 grams of potassium persulfate was weighed and dissolved in 2 grams of deionized water, and 0.024 grams of catalyst TEMED was added to the beaker at the same time, and stirred evenly to form a prepolymer solution.

Nitrogen gas was bubbled into the prepolymer solution for 30 minutes to remove residual oxygen in the solution. Then inject the solution into a glass tube with a length of 60 mm and a diameter of 5 mm, keep at 30° C., and react for 24 hours. The preliminarily obtained gel was placed in a thermal incubator at 40° C. and kept warm for 10 days to obtain a nanogel.

The mechanical property of composite gel and the water-absorbing property test adopt in 2006 macromolecule letter 27 volumes, and the method mentioned in the report of people such as Zhu is detected, and its result is as follows:

Strength: 195kPa

Elongation: 2331%

Resilience: 90-95%

Water absorption: 1265 times.

Example 3

Weigh 1.5 grams of clay and dissolve it in 28 grams of deionized water solution, place it in a 150ml beaker and stir for 2 hours. After the clay is completely dissolved in the water solution to form a uniform and stable solution, weigh 6 grams of AAm and add it to the beaker to continue stirring. At the same time, 0.03 grams of potassium persulfate was weighed and dissolved in 2 grams of deionized water, and 0.024 grams of catalyst TEMED was added to the beaker at the same time, and stirred evenly to form a prepolymer solution.

Nitrogen gas was bubbled into the prepolymer solution for 40 minutes to remove residual oxygen in the solution. Then inject the solution into a glass tube with a length of 60 mm and a diameter of 5 mm, keep it at 35° C., and react for 30 hours. The preliminarily obtained gel was placed in a thermal incubator at 45° C. and kept warm for 15 days to obtain a nanogel.

The mechanical property of composite gel and the water-absorbing property test adopt in 2006 macromolecule letter 27 volumes, and the method mentioned in the report of people such as Zhu is detected, and its result is as follows:

Tensile strength: 217Kpa

Elongation: 2362%

Compression resilience: 90-95%

Water absorption: 861 times

Example 4

Weigh 3 grams of clay and dissolve it in 28 grams of deionized aqueous solution, place it in a 150ml beaker and stir for 2 hours, until the clay is completely dissolved in the aqueous solution to form a uniform and stable solution, weigh 3 grams of AAm and add it to the beaker to continue stirring. At the same time, weigh 0.03 grams of KPS and dissolve in 2 grams of deionized water, and add 0.024 grams of catalyst TEMED into the beaker at the same time, stir evenly to form a pre-polymerization liquid.

Bubble nitrogen into the prepolymerization solution for 20 minutes to remove residual oxygen in the solution. Then inject the solution into a glass tube with a length of 60 mm and a diameter of 5 mm, keep at 30° C., and react for 24 hours. The preliminarily obtained gel was placed in a thermal incubator at 40° C. and kept warm for 10 days to obtain a nanogel.

The mechanical property of composite gel and the water-absorbing property test adopt in 2006 macromolecule letter 27 volumes, and the method mentioned in the report of people such as Zhu is detected, and its result is as follows:

Strength: 222kPa

Elongation: 2062%

Resilience: 90-95%

Water absorption: 1784 times

Example 5

Weigh 3 grams of clay and dissolve it in 28 grams of deionized aqueous solution, place it in a 150ml beaker and stir for 2 hours, until the clay is completely dissolved in the aqueous solution to form a uniform and stable solution, weigh 4.5 grams of AAm and add it to the beaker to continue stirring. At the same time, weigh 0.03 grams of KPS and dissolve in 2 grams of deionized water, and add 0.024 grams of catalyst TEMED into the beaker at the same time, stir evenly to form a pre-polymerization solution.

Bubble nitrogen into the prepolymerization solution for 10 minutes to remove residual oxygen in the solution. Then inject the solution into a glass tube with a length of 60 mm and a diameter of 5 mm, keep at 30° C., and react for 24 hours. The preliminarily obtained gel was placed in a thermal incubator at 40° C. for 15 days to obtain a nanogel.

The mechanical property of composite gel and the water-absorbing property test adopt in 2006 macromolecule letter 27 volumes, and the method mentioned in the report of people such as Zhu is detected, and its result is as follows:

Strength: 325kPa

Elongation: 2053%

Resilience: 90-95%

Water absorption: 1300 times

Example 6

Weigh 3 grams of clay and dissolve it in 28 grams of deionized aqueous solution, place it in a 150ml beaker and stir for 2 hours, until the clay is completely dissolved in the aqueous solution to form a uniform and stable solution, weigh 6 grams of AAm and add it to the beaker to continue stirring. At the same time, weigh 0.03 grams of KPS and dissolve in 2 grams of deionized water, and add 0.024 grams of catalyst TEMED into the beaker at the same time, stir evenly to form a pre-polymerization solution.

Nitrogen gas was bubbled into the prepolymer solution for 60 minutes to remove residual oxygen in the solution. Then inject the solution into a glass tube with a length of 60 mm and a diameter of 5 mm, keep at 30° C., and react for 24 hours. The preliminarily obtained gel was placed in a thermal incubator at 40° C. for 20 days to obtain a nanogel.

The mechanical property of composite gel and the water-absorbing property test adopt in 2006 macromolecule letter 27 volumes, and the method mentioned in the report of people such as Zhu is detected, and its result is as follows:

Strength: 397Kpa

Elongation: 1938%

Resilience: 90-95%

Water absorption: 748 times.

Claims (4)

1. the preparation method of a Nanometer composite hydrogel is characterized in that, comprises the steps: the polymerization under 25～35 ℃ of conditions of pre-polymerization liquid, polymerization time is 20～30h, then with polymerisate under 35～45 ℃ temperature, be incubated 5～20 days, promptly obtain said Nanometer composite hydrogel;

The component of said pre-polymerization liquid and weight content, the weight based on water comprises:

Monomer accounts for the 10-20% of water weight

Linking agent accounts for the 5-10% of water weight

Initiator accounts for the 0.1-0.2% of water weight

Catalyzer accounts for the 0.1-0.2% of water weight

Said monomer is selected from acrylamide;

Said linking agent is selected from the hectorite through the trisodium phosphate modification, and its chemical structure of general formula is:

Mg _5.34Li _0.66Si ₈O ₂₀(OH) ₄Na _0.66。

2. the preparation method of Nanometer composite hydrogel according to claim 1 is characterized in that, said initiator is selected from a kind of in fine of Potassium Persulphate, ammonium persulphate, azo two isobutyls.

3. the preparation method of nano-hydrogel according to claim 1 is characterized in that, said catalyzer is selected from a kind of in N,N,N, trolamine, the sodium thiosulfate.

4. according to the preparation method of each described Nanometer composite hydrogel of claim 1～3, it is characterized in that, linking agent is added in the entry soak into earlier, peel off, form a kind of linking agent lamella, thickness is 1-2nm, diameter 20-30nm joins other raw materials in the cross-linking agent aqueous solution then and reacts.