阅读说明：本技术 一种自交联形状记忆杜仲胶复合材料及其制备方法和应用 (Self-crosslinking shape memory gutta-percha composite material and preparation method and application thereof ) 是由 岳冬梅 祁鑫 谢飞 张继川 张立群 于 2019-09-20 设计创作，主要内容包括：本发明涉及形状记忆材料制备技术领域,具体涉及一种自交联形状记忆杜仲胶复合材料及其制备方法和应用。所述自交联形状记忆杜仲胶复合材料的制备方法,包括：(1)在有机溶剂及催化剂的存在下,利用过氧化物对杜仲胶的碳碳双键进行环氧化反应,得到产物A；(2)在酸性条件下,所述产物A在正硅酸酯类交联剂、去离子水的作用下发生开环及自交联反应,得到复合材料。采用该方法得到的自交联形状记忆杜仲胶复合材料具有无毒无害、绿色环保的优点,且形状记忆转变温度可调控。所述自交联形状记忆杜仲胶复合材料在生物领域、智能传感领域等方面具有重要应用前景。(The invention relates to the technical field of shape memory material preparation, in particular to a self-crosslinking shape memory gutta-percha composite material and a preparation method and application thereof. The preparation method of the self-crosslinking shape memory gutta-percha composite material comprises the following steps: (1) in the presence of an organic solvent and a catalyst, carrying out epoxidation reaction on carbon-carbon double bonds of the gutta-percha by using peroxide to obtain a product A; (2) under the acidic condition, the product A is subjected to ring-opening and self-crosslinking reaction under the action of an orthosilicate crosslinking agent and deionized water to obtain the composite material. The self-crosslinking shape memory gutta-percha composite material obtained by the method has the advantages of no toxicity, no harm, environmental protection and adjustable shape memory transition temperature. The self-crosslinking shape memory gutta-percha composite material has important application prospect in the fields of biology, intelligent sensing and the like.)

1. A preparation method of a self-crosslinking shape memory gutta-percha composite material is characterized by comprising the following steps:

(1) in the presence of an organic solvent and a catalyst, carrying out epoxidation reaction on carbon-carbon double bonds of the gutta-percha by using peroxide to obtain a product A;

(2) under the acidic condition, the product A is subjected to ring-opening and self-crosslinking reaction under the action of an orthosilicate crosslinking agent and deionized water to obtain the composite material.

2. The method for preparing the self-crosslinking shape memory gutta-percha composite material as in claim 1, wherein in the step (1), the epoxidation reaction is performed under the following conditions: the temperature is 20-80 ℃, preferably 30-40 ℃.

3. The preparation method of the self-crosslinking shape memory gutta-percha composite material as in claim 1 or 2, wherein the catalyst is an organic acid, preferably one or more of formic acid, acetic acid, benzoic acid or salicylic acid;

preferably, the molar ratio of the catalyst to the carbon-carbon double bond of the gutta percha is (0.01-0.20): 1, preferably the molar ratio is (0.05-0.15): 1.

4. the method for preparing a self-crosslinking shape-memory gutta-percha composite material as in any one of claims 1 to 3, wherein in the step (1), said peroxide is selected from hydrogen peroxide and/or peracetic acid;

preferably, the molar ratio of the peroxide to the carbon-carbon double bond of the gutta percha is (0.01-0.20): 1, preferably the molar ratio is (0.05-0.15): 1.

5. the preparation method of the self-crosslinking shape memory gutta-percha composite material according to any one of claims 1 to 4, wherein in the step (2), the pH of the system is 1 to 4 during the ring-opening and self-crosslinking reaction;

and/or the conditions of the ring-opening and self-crosslinking reaction are as follows: the temperature is 25-60 ℃.

6. The method for preparing a self-crosslinking shape memory gutta-percha composite material as in any one of claims 1 to 5, wherein in the step (2), the orthosilicic acid ester crosslinking agent is selected from one or more of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, or butyl orthosilicate;

preferably, the amount of the cross-linking agent is 10-100% of the mass of the gutta percha.

7. The method for preparing a self-crosslinking shape-memory gutta-percha composite material as in any one of claims 1 to 6, wherein in the step (1), the organic solvent is one or more selected from toluene, xylene, chloroform or n-hexane;

and/or in the step (1), the concentration of the eucommia ulmoides gum in the organic solvent is 1-6%, and the preferable concentration is 2-5%;

and/or in the step (2), the amount of the deionized water is 10-200% of the mass of the gutta percha, and the preferential amount is 50-100%.

8. The preparation method of the self-crosslinking shape memory gutta-percha composite material according to any one of claims 1 to 7, further comprising post-treatment of the reaction solution obtained in the step (2); the post-processing comprises: and (3) carrying out precipitation, washing, drying and curing treatment on the reaction liquid obtained in the step (2).

9. The self-crosslinking shape memory gutta-percha composite material obtained by the preparation method of any one of claims 1 to 8.

10. The self-crosslinking shape memory gutta percha composite material as recited in claim 9, which is applied to the fields of biology and intelligent sensing.

Technical Field

The invention relates to the technical field of shape memory material preparation, in particular to a self-crosslinking shape memory gutta-percha composite material and a preparation method and application thereof.

Background

Shape memory materials refer to materials that have the function of "memorizing" macroscopic shapes, which can be edited or "set" into a particular shape under a particular temperature or stress condition, and then can be restored to the original state under a stimulus such as heat, electricity, or the environment. Shape memory materials have attracted considerable attention in recent years from researchers due to their potential utility in sensors, actuators, smart devices, information recording, biomedical applications, and the like.

As an important shape memory material, thermotropic Shape Memory Polymers (SMPs) can be divided into four major classes, chemically cross-linked thermosets, chemically cross-linked semi-crystalline rubbers, physically cross-linked thermosets and physically cross-linked semi-crystalline rubbers. The thermotropic shape memory polymer has shape memory transition temperature (T)_trans) T of a material in general_gOr T_m,. When the ambient temperature is higher than T_transWhile, the material can be edited; subsequently reducing the ambient temperature to T_transThe temporary shape formed by editing is fixed; when the ambient temperature is again above T_transWhen the material is used, the original shape of the material can be recovered, and the shape memory function is realized. Compared with the traditional shape memory alloy, the thermotropic shape memory polymer has many advantages, such as high deformation, low cost, good biocompatibility, degradability, adjustable transformation temperature, easy processing and the like, so that the research and development of the thermotropic shape memory polymer have important significance.

The biobased material is a green renewable resource, and the development and utilization of the biobased material can reduce the consumption of petrochemical resources and reduce the influence on the environment, so that the prospect is very wide. Gutta-percha is a special bio-based polymer material in China, is widely distributed in various regions of China, and has the advantages that gutta-percha resources in China account for about 99% of the world and are unique. Wherein the gutta percha has a structural formula of trans-isoprene (TPI), is semi-crystalline rubber, and can be used for preparing shape memory materials.

However, the traditional gutta percha shape memory material needs to be crosslinked by using a vulcanizing agent, and a small molecular auxiliary agent needs to be added, so that not only can the environment be influenced, but also the prepared material has certain toxicity, and is not beneficial to wide application, especially application in the biological field. Therefore, the development of the green nontoxic self-crosslinking gutta percha shape memory material has important significance.

Disclosure of Invention

In order to solve the technical problems, the invention provides a preparation method of a self-crosslinking shape memory gutta-percha composite material. The self-crosslinking shape memory gutta-percha composite material obtained by the method has the advantages of no toxicity, no harm, environmental protection and adjustable shape memory transition temperature. The self-crosslinking shape memory gutta-percha composite material has important application prospects in the fields of biology (such as orthodontics), intelligent sensing (such as temperature sensors) and the like.

The preparation method of the self-crosslinking shape memory gutta-percha composite material comprises the following steps:

(1) in the presence of an organic solvent and a catalyst, carrying out epoxidation reaction on carbon-carbon double bonds of the gutta-percha by using peroxide to obtain a product A;

(2) under the acidic condition, the product A is subjected to ring-opening and self-crosslinking reaction under the action of an orthosilicate crosslinking agent and deionized water to obtain the composite material.

The invention introduces reactive groups (hydroxyl groups) on the gutta percha molecular chain, on one hand, the gutta percha molecular chain can be used for self-crosslinking to form a network structure; on the other hand, the melting temperature can be adjusted, and further the shape memory transition temperature can be adjusted. The preparation method does not use a vulcanization crosslinking agent and a small molecular auxiliary agent, and the obtained self-crosslinking shape memory gutta-percha composite material has the advantages of no toxicity, no harm, greenness and environmental protection.

In the step (1), the epoxidation reaction conditions are as follows: the temperature is 20-80 ℃, and preferably 30-40 ℃; the time is 3-6 h.

In the step (1), the catalyst is an organic acid, preferably one or more of formic acid, acetic acid, benzoic acid or salicylic acid.

In the step (1), the molar ratio of the catalyst to the carbon-carbon double bond of the gutta percha is (0.01-0.20): 1, preferably the molar ratio is (0.05-0.15): 1. research shows that the catalytic effect is better in the range of the molar ratio.

In the step (1), the peroxide is selected from hydrogen peroxide and/or peracetic acid.

In the step (1), the molar ratio of the peroxide to the carbon-carbon double bond of the gutta percha is (0.01-0.20): 1, preferably the molar ratio is (0.05-0.15): 1. research shows that the epoxidation effect is better in the range of the molar ratio.

In the step (1), the organic solvent is one or more selected from toluene, xylene, chloroform and n-hexane. The concentration of the gutta-percha in the organic solvent is 1-6%, and the preferable concentration is 2-5%, so that the reaction can be more fully carried out.

In the step (2), the pH value of the system is 1-4 in the ring-opening and self-crosslinking reaction process. Studies have shown that too low a pH increases the cost of work-up, while too high a pH is detrimental to the ring-opening reaction. The pH of the system can be adjusted by using a common pH adjusting agent, preferably one or more of hydrochloric acid, nitric acid, sulfuric acid, formic acid or acetic acid.

In the step (2), the conditions of the ring-opening and self-crosslinking reaction are as follows: the temperature is 25-60 ℃, and the time is 1-3 h. The melting temperature and thus the transition temperature can be adjusted by controlling the reaction conditions.

In the step (2), the cross-linking agent is one or more selected from methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate and butyl orthosilicate.

In the step (2), the amount of the orthosilicate crosslinking agent is 10-100%, preferably 20-60% of the mass of the gutta percha.

In the step (2), the amount of the deionized water is 10-200% of the mass of the gutta percha, and preferably 50-100%.

The preparation method also comprises the step of post-treating the reaction liquid obtained in the step (2). The post-processing comprises: and (3) carrying out precipitation, washing, drying and curing treatment on the reaction liquid obtained in the step (2).

Wherein, the organic solvent adopted for precipitation is selected from one or more of acetone, methanol or ethanol.

The curing conditions are as follows: the temperature is 130 ℃ and 180 ℃, and the temperature is preferably 150 ℃; the pressure is 10-20MPa, preferably 15 MPa; the time is 10-60min, preferably 30 min.

As one embodiment of the present invention, a method for preparing a self-crosslinking shape-memory gutta-percha composite material comprises: dissolving the eucommia ulmoides gum in an organic solvent to prepare a solution, adding an organic acid and peroxide, and reacting for 3-6 h at the temperature of 20-80 ℃; and then adjusting the pH value of the system to 1-4, adding an orthosilicate crosslinking agent and deionized water, reacting for 1-3 h at 25-60 ℃, precipitating, washing, drying, and finally curing for 30min at 150 ℃ and 15 MPa.

The invention also provides the self-crosslinking shape memory gutta-percha composite material prepared by the preparation method. The self-crosslinking shape memory gutta-percha composite material has hydroxyl groups, is non-toxic and harmless, is green and environment-friendly, and has adjustable shape memory transition temperature.

The invention also provides application of the self-crosslinking shape memory gutta-percha composite material in the fields of biology (such as orthodontics), intelligent sensing (such as temperature sensors) and the like.

The invention has the following beneficial effects:

the innovation of the invention is that: by introducing reactive groups into the gutta percha molecular chain, on one hand, the gutta percha can be used for self-crosslinking to form a network structure; on the other hand, the melting temperature can be adjusted, and further the shape memory transition temperature can be adjusted. The self-crosslinking shape memory gutta-percha composite material prepared by the invention takes the bio-based gutta-percha as a raw material, does not need to add a crosslinking agent such as sulfur and DCP and a small molecular auxiliary agent, is nontoxic and harmless, is green and environment-friendly, and has adjustable shape memory transition temperature. The composite material has important application prospect in the fields of biology (such as orthodontics), intelligent sensing (such as temperature sensors) and the like.

Drawings

Fig. 1 is a fourier infrared spectrum of a self-crosslinking shape-memory gutta-percha composite material prepared in the conventional gutta-percha and example 1.

Fig. 2 is a differential scanning calorimetry curve of the self-crosslinking shape-memory gutta-percha composite materials prepared in example 1, example 2, example 3 and example 4.

FIG. 3 is a shape memory cycle curve of the self-crosslinking shape memory gutta-percha composite material prepared in example 5.

Fig. 4 is a strain recovery curve of the self-crosslinking shape memory gutta-percha composite materials prepared in example 1, example 2, example 3 and example 4 in the shape memory test temperature rising process.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention. The examples do not show the specific techniques or conditions, according to the technical or conditions described in the literature in the field, or according to the product specifications. The reagents or instruments used are conventional products available from regular distributors, not indicated by the manufacturer.