INTERACTION OF SILICA WITH SILICONE RUBBER UPON HEAT AGEING
二氧化硅填料与硅橡胶在热老化时的作用

The heat ageing interaction of silicone rubber with three of fumed silica having different surface property was studied. The rubber compounds and vulcanizates were swelled in toluene and in toluene over ammonia; bound rubber as well as swelling degree of the vulcanizate were determined. It was found that a significant amount of chemical crosslink is formed between filler and rubber chain upon heat treatment, meanwhile the interfacial hydrogen bond is transformed to chemical linkage. The formation of chemical linkage as well as hydrogen bondis greatly reduced by surface modification of the filler before or during compounding.