低压缩永久变形热硫化硅橡胶的制备

Preparation of Low Compression Set HTV Silicone Rubber

以甲基乙烯基硅橡胶为基料,白炭黑为填料,开发了一款低压缩永久变形的硅橡胶产品,研究了温度、耐热剂、不同品牌生胶、结构化控制剂对混炼胶压缩永久变形性能的影响,并通过配方设计,最终提升了硅橡胶的压缩永久变形性能。结果表明:测试温度、生胶种类、耐热剂和结构化控制剂对改善压缩永久变形性能的作用较小;较佳配方为:75份甲基乙烯基生胶110-8S、20份甲基乙烯基生胶110-3S、5份甲基乙烯基生胶110-7SK、45份沉淀法白炭黑658B、2.2份羟基硅油、1.0份乙烯基羟基硅油、0.4份含氢硅油、0.1份硬脂酸;采用该配方的产品,其177℃×22 h下的压缩永久变形为12.0%,能满足市场需求。

The silicone rubber with excellent compression set performance was prepared with methyl vinyl silicone rubber as base material and silica as filler. The effects of test temperature, heat-resistant agent, raw rubber of different brands and structural control agent on the compression set properties of silicone rubber were studied, and the compression set properties of silicone rubber were improved by formula design. The results show that temperature, raw rubber of different brands, heat-resistant agent and structural control agent have little effect on the compression set properties of the rubber. The better formula is as follows: 75 phr of methyl vinyl rubber 110-8S, 20 phr of methyl vinyl rubber 110-3S, 5 phr of methyl vinyl rubber 110-7SK, 45 phr of precipitated silica 658B, 2.2 phr of hydroxyl silicone oil, 1.0 phr of vinyl hydroxyl silicone oil, 0.4 phr of hydrogen-containing silicone oil and 0.1 phr of stearic acid. The prepared product has a permanent compression deformation of 12.0% at 177 ℃×22 h, which meets the market demands.