阅读说明：本技术 一种耐高温聚氨酯橡胶及其制备方法 (High-temperature-resistant polyurethane rubber and preparation method thereof ) 是由 王国辉 张耐民 付继伟 陈红波 刘金峰 廖锡广 岳勇 赵继亮 于 2020-05-07 设计创作，主要内容包括：本发明涉及一种耐高温聚氨酯橡胶及其制备方法,属于聚氨酯材料技术领域,也属于橡胶性能改性技术领域,属于柔性热防护技术领域。本发明制备的产品的硬度提高了11％-13％,拉伸强度提高了27％-抗臭氧老化和抗热空气老化性能提高了33％-最大使用温度为145-163℃。(The invention relates to high-temperature-resistant polyurethane rubber and a preparation method thereof, belongs to the technical field of polyurethane materials, also belongs to the technical field of rubber performance modification, and belongs to the technical field of flexible thermal protection. The hardness of the product prepared by the method is improved by 11-13%, the tensile strength is improved by 27%, the ozone aging resistance and the hot air aging resistance are improved by 33%, and the maximum use temperature is 145-163 ℃.)

1. A high-temperature resistant polyurethane rubber is characterized in that: the raw materials of the high-temperature resistant polyurethane rubber comprise oligomer polyol, diisocyanate, a chain extender and organic tin as catalysts, wherein the mass portion of the diisocyanate is 1 part, the mass portion of the oligomer polyol is 4 parts, the mass portion of the organic tin catalyst is 0.005 part,

when the chain extender is phenylmethyl cyclotrisilazane, the mass part of the phenylmethyl cyclotrisilazane is 0.8-1.2;

when the chain extender is hexaphenylcyclotrisilazane, the mass portion of the phenylmethylcyclotrisilazane is 1.2-1.8.

2. The high-temperature-resistant polyurethane rubber according to claim 1, wherein: the oligomer polyol is diethylene glycol.

3. The high-temperature-resistant polyurethane rubber according to claim 1, wherein: the diisocyanate is 1, 6-hexamethylene diisocyanate.

4. The high-temperature-resistant polyurethane rubber according to claim 1, wherein: the organic tin catalyst is dibutyltin diacetate.

5. A preparation method of high-temperature-resistant polyurethane rubber is characterized by comprising the following steps:

firstly, mixing oligomer polyol and diisocyanate, and stirring at the mixing temperature of 20-30 ℃, the stirring speed of 60-120 r/min and the stirring time of 10-20min to obtain a mixture A;

secondly, adding the chain extender into the mixture A obtained in the first step, and stirring at the stirring speed of 150-;

thirdly, adding an organic tin catalyst into the mixture B, and heating to obtain high-temperature-resistant polyurethane rubber; the heating temperature is 40-60 ℃, the heating time is 10-15min, wherein the chain extender is phenyl methyl cyclotrisilazane or hexaphenyl cyclotrisilazane.

6. The method for preparing high temperature resistant polyurethane rubber according to claim 5, wherein the method comprises the following steps: in the first step, the stirring speed is 60-120 r/min.

7. The method for preparing high temperature resistant polyurethane rubber according to claim 5, wherein the method comprises the following steps: in the first step, the stirring time is 10-20 min.

8. The method for preparing high temperature resistant polyurethane rubber according to claim 5, wherein the method comprises the following steps: in the second step, the stirring speed is 150-.

9. The method for preparing high temperature resistant polyurethane rubber according to claim 5, wherein the method comprises the following steps: in the second step, the stirring time is 5-10 min.

10. The method for preparing high temperature resistant polyurethane rubber according to claim 5, wherein the method comprises the following steps: calculated by taking 1 part by mass of diisocyanate, 4 parts by mass of oligomer polyol, 0.005 part by mass of organotin catalyst,

when the chain extender is phenylmethyl cyclotrisilazane, the mass part of the phenylmethyl cyclotrisilazane is 0.8-1.2;

when the chain extender is hexaphenylcyclotrisilazane, the mass part of the phenylmethylcyclotrisilazane is 1.2-1.8;

the oligomer polyol is diethylene glycol;

the diisocyanate is 1, 6-hexamethylene diisocyanate;

the chain extender is phenyl methyl cyclotrisilazane or hexaphenyl cyclotrisilazane;

the organic tin catalyst is dibutyltin diacetate.

Technical Field

The invention relates to high-temperature-resistant polyurethane rubber and a preparation method thereof, belongs to the technical field of polyurethane materials, also belongs to the technical field of rubber performance modification, and belongs to the technical field of flexible thermal protection, wherein the temperature resistance means that the polyurethane rubber can resist 163 ℃ of ion-resistant polyurethane rubber.

Background

The polyurethane rubber is a series of elastomer materials containing more urethane groups on a polymer main chain, and is actually polyurethane rubber, which is simply referred to as polyurethane rubber or urethane rubber or polyurethane elastomer. The polymer chain contains, in addition to urethane groups, ester groups, ether groups, urea groups, aromatic groups, aliphatic chains, and the like. Usually formed by reacting an oligomeric polyol, a polyisocyanate and a chain extender. The main chain of the polyurethane rubber molecule is composed of a flexible chain segment and a rigid chain segment which are embedded: the soft segment is also called soft segment and is composed of oligomer polyol (such as polyester, polyether, polybutadiene and the like); the hard segment, also known as a hard segment, is composed of a reaction product of a diisocyanate (e.g., TDI, MDI, etc.) and a small molecule chain extender (e.g., a diamine, a diol, etc.). The soft segment accounts for a greater proportion than the hard segment. The soft and hard chain segments have different polarities, and the hard chain segments have strong polarity and are easy to gather together to form a plurality of micro-regions which are divided into soft chain segment phases, which are called microphase separation structures, and the physical and mechanical properties of the microphase separation structures have great relation with the microphase separation degree. The polyurethane rubber forms different structures and varieties according to different used raw materials and proportions, reaction modes, conditions and the like. Polyurethane elastomers have traditionally been classified according to processing methods into cast polyurethane elastomers, compounded polyurethane elastomers and thermoplastic polyurethane elastomers. Because of different used raw materials, synthesis and processing methods, application purposes and the like, reaction injection type polyurethane elastomers and solution dispersion type polyurethane elastomers are also produced; according to the formed form, the material is divided into a solid system and a liquid system; there are also those classified according to the chemical composition of the raw materials, and there are generally polyesters and polyethers, and thus there are polyether polyurethane elastomers and polyester polyurethane elastomers. The main advantages of polyurethane rubber are: has the advantages of good mechanical property (high hardness and good strength), good aging resistance (ozone resistance, radiation resistance and damp-heat resistance), good conductivity and the like, which cannot be compared with common rubber. Although the polyurethane rubber has many advantages, the polyurethane rubber has the defect of poor temperature resistance, the application range of the polyurethane rubber in a relatively high-temperature environment is obviously limited due to the fact that the using temperature ranges are about minus 30 ℃ to plus 80 ℃, at present, the polyurethane rubber is improved in temperature resistance by adding compounding agents, the common heat-resistant and heat-transfer compounding agents comprise asbestos powder, mica powder, graphite powder, carbon black, pottery clay, zinc oxide, magnesium carbonate and the like, and under special conditions, aluminum powder or lead powder can be used. Many researchers now try to improve the temperature resistance of the polyurethane rubber by changing the structure of the soft segment or the hard segment of the polyurethane rubber, even the chain extender. In addition, the research on the influence of the silicon nitride compound on the compression deformation of the silicon rubber shows that the hexaphenylcyclotrisilazane is very effective in reducing the compression deformation of the vinyl silicone rubber, and can reduce the compression deformation of the vinyl silicone rubber from 30% to 12% after 22 hours at 250 ℃. Most importantly, research results show that hexaphenylcyclotrisilazane introduced into a molecular chain can remarkably improve the temperature resistance of the molecular chain. Wu Xiaofeng et al synthesized high molecular weight poly (diethylene glycol adipate) by chain-extending a cyclic silicon nitrogen compound hexaphenylcyclotrisilazane as a chain extender, and found that hexaphenylcyclotrisilazane is a good chain extender for alcohol ester polymers, can extend a polyester oligomer into a high molecular weight aliphatic polyester, and has few side reactions. At present, there is no literature showing the application of hexaphenylcyclotrisilazane as a chain extender to polyurethane rubbers.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: overcomes the defects of the prior art and provides high-temperature-resistant polyurethane rubber and a preparation method thereof.

The technical solution of the invention is as follows:

the high temperature resistant polyurethane rubber comprises the raw materials of oligomer polyol, diisocyanate, a chain extender and organic tin as catalysts, wherein the mass part of the diisocyanate is 1 part, the mass part of the oligomer polyol is 4 parts, the mass part of the organic tin catalyst is 0.005 part,

when the chain extender is phenylmethyl cyclotrisilazane, the mass part of the phenylmethyl cyclotrisilazane is 0.8-1.2;

when the chain extender is hexaphenylcyclotrisilazane, the mass part of the phenylmethylcyclotrisilazane is 1.2-1.8;

the oligomer polyol is diethylene glycol;

the diisocyanate is 1, 6-hexamethylene diisocyanate;

the chain extender is phenyl methyl cyclotrisilazane or hexaphenyl cyclotrisilazane;

the organic tin catalyst is dibutyltin diacetate.

A preparation method of high-temperature-resistant polyurethane rubber comprises the following steps:

firstly, mixing oligomer polyol and diisocyanate, and stirring at the mixing temperature of 20-30 ℃, the stirring speed of 60-120 r/min and the stirring time of 10-20min to obtain a mixture A;

secondly, adding the chain extender into the mixture A obtained in the first step, and stirring at the stirring speed of 150-;

thirdly, adding an organic tin catalyst into the mixture B, and heating to obtain high-temperature-resistant polyurethane rubber; the heating temperature is 40-60 ℃, the heating time is 10-15min, wherein the chain extender is phenyl methyl cyclotrisilazane or hexaphenyl cyclotrisilazane.

Calculated by taking 1 part by mass of diisocyanate, 4 parts by mass of oligomer polyol, 0.005 part by mass of organotin catalyst,

when the chain extender is phenylmethyl cyclotrisilazane, the mass part of the phenylmethyl cyclotrisilazane is 0.8-1.2;

when the chain extender is hexaphenylcyclotrisilazane, the mass part of the phenylmethylcyclotrisilazane is 1.2-1.8;

the oligomer polyol is diethylene glycol;

the diisocyanate is 1, 6-hexamethylene diisocyanate;

the chain extender is phenyl methyl cyclotrisilazane or hexaphenyl cyclotrisilazane;

the organic tin catalyst is dibutyltin diacetate.

And testing the temperature resistance, mechanical properties (hardness and strength) and aging resistance (ozone resistance and hot air aging resistance) of the obtained high-temperature-resistant polyurethane rubber, wherein the temperature resistance takes the highest temperature when the tensile strength begins to reduce as the upper temperature use limit, the hardness test adopts the measurement of the hardness of GB/T6031-1998 vulcanized rubber or thermoplastic rubber, the strength test adopts the measurement of the tensile stress strain performance of GB/T528-1998 vulcanized rubber or thermoplastic rubber, and the ozone aging resistance and the air aging resistance adopt the GB/T7762-2003 vulcanized rubber or thermoplastic rubber static tensile test and the GB/T3512-2001 vulcanized rubber or thermoplastic rubber hot air accelerated aging and heat resistance test respectively.

The structural formula of hexaphenylcyclotrisilazane is as follows:

the structural formula of phenylmethylcyclotrisilazane is as follows:

advantageous effects

The hardness of the product prepared by the method is improved by 11-13%, the tensile strength is improved by 27%, the ozone aging resistance and the hot air aging resistance are improved by 33%, and the maximum use temperature is 145-163 ℃.

Detailed Description

The invention is further illustrated by the following examples, without restricting its application to the examples given.