The Effect of Fine Powdered Silica on Theproperties of Rubber

Abstract

The fine powdered silica containing small amounts of calcium salts, synthesized from acid clay, is suitable as a reinforcing filler for rubber. The properties of this powder was compared with those of various fine powdered silica synthesized by the ordinary soldium silicate method.(1) The fine powdered silica synthesized from active silica hydrogel and others by the ordinary sodium silicate method were added to rubber in various amounts. The effects of this addition to rubber was compared. It was found that there is little difference in character except that the flexure resistance and abrasion resistance of the former is very good. (In actual practice, those properties are suitable as a filler for rubber sole compounds.) (2) When the comparison of (1) is made for the same hardness, the same tendency becomes more remarkable.(3) It is known from the data of (2), obtained for the same hardness, that the modulus is almost proportional to abrasion.(4) The mixed system of thiazol and thiurum compounds gives satisfactory effects on rubber in general when it is used as a accelerator of rubber to which fine powdered silica synthesized from active silica hydrogel is added.

Influence of Silica on Vulcanization by Sulphur/Cbs in Isoprene Rubber

“…Scorch has been identified as a phenomenon occurring when moisture in the master batch accelerates vulcanisation [16]. Numerous silanol groups exist on the surface of silica particles, and many water molecules are adsorbed [3].…”