Fluorine-containing elastomer with excellent low temperature and liquid resistance and preparation method thereof

Abstract

The invention discloses a fluorine-containing elastomer with excellent low temperature and liquid resistance and a preparation method thereof. The elastomer is prepared by thermally kneading and mixing the following components in parts by weight: 100 parts of fluororubber, 0-30 parts of acid absorbent, 0-35 parts of calcium hydroxide, 0-50 parts of reinforcing filler, 0-10 parts of plasticizer, 0.5-5 parts of vulcanizing agent, 0-5 parts of organic wax, 0.2-2 parts of accelerant, 1-30 parts of fluorosilicone alkane ester and 1-10 parts of multifunctional additive LCA. The fluorine-containing elastomer and the preparation method, which are provided by the invention, have the beneficial effects that the preparation method is simple and practicable and is lower in production cost; by adding fluorosilane ester to the components of the fluorine-containing elastomer and simultaneously matching fluorosilane ester with the multifunctional additive LCA, the low temperature brittleness temperature of an existing fluororubber compound is better decreased (Tg of the fluorine-containing elastomer can be reduced by about 5-10 DEG C) after the existing fluororubber compound undergoes primary or secondary vulcanization; meanwhile, the effects on the liquid resistance of the fluororubber are very small, so that the fluororubber can be more widely applied.

Description

Technical field [0001] The present invention involves a fluoride elastic body and its preparation methods with excellent low temperature and liquid resistance, which belongs to the field of rubber technology. Background technique [0002] Fluorine rubber refers to a polymer elastic body with fluorine atoms on the carbon atom of the molecular main chain or side chain.In the fluorine rubber molecular structure, the C-F key (435 ~ 485kJ / mol) is large, and the total price radius (0.064nm) of the fluorine atomic price (0.064nm) is equivalent to half of the C-C key.Getting up, therefore, fluorine rubber has a high degree of chemical stability and thermal stability. It is the best -resistant medium resistance in all elastic body. It can be widely used in space, automobiles, machinery, petrochemicals, etc. [0003] However, one or more co -concentrations or mixtures containing dual or trigger conventional fluorine -containing unsaturated monomers have a prominent disadvantage of fluorine...

AI Technical Summary

Problems solved by technology

[0003] However, one or more copolymers or mixtures containing dibasic or tribasic conventional fluorine-containing ethylenically unsaturated monomers have an outstanding shortcoming in the fluororubber prepared by the existing composition technology: its low temperature performance is too poor (Generally Tg is not lower than -21°C), which is far from meeting the market's requirements for its performance, especially in aviation and aerospace

At present, there are two main ways to solve this problem: one is to use other materials to replace fluorine rubber. It is relatively expensive, and its high temperature stability is not ideal; another method is to add a third or fourth monomer in the synthesis stage to reduce the Tg of fluororubber, thereby improving the problem of insufficient low temperature flexibility, such as in VDF, On the basis of TFE monomer, a new monomer—perfluoromethyl vinyl ether (PMVE) is introduced for copolymerization, but this method requires the addition of a considerable amount of polymerized monomer PMVE, and the amount is usually 20% to 40% (mol fraction). Between, not only the production process is complicated, but also the production cost is very expensive

In the existing production, the low-temperature performance of fluororubber is usually improved by introducing silicone segments or using them in combination with silicone rubber; however, since silicone rubber and fluororubber are completely incompatible, crosslinking agents and crosslinking mechanisms It is also completely different, it is difficult to add and form a stable cross network structure; similarly, due to the poor liquid resistance of silicone, although the introduction of silicone can improve the low temperature resistance of organic fluororubber, it will affect the resistance of organic fluororubber. Liquid performance, especially high temperature liquid resistance has a great influence

Images