The Role of Metal Oxides as Activators of Vulcanization

Abstract

1. The activation effect of metal oxides on the process of culvanization of nonpigmented compounds of rod polymerized sodium butadiene rubber differs from the effect in rodless polymerized rubber. In the latter case zinc oxide not only is not an activator but it retards the vulcanization process. 2. The role of activators depends, to a large degree, on the type of vulcanization accelerator and active filler used. 3. Metal oxides increase the amount of structure formation in the vulcanizate. 4. With regard to butadiene styrene rubber (SKS-30A), calcium hydroxide appears to have stronger activating effect on vulcanization than zinc oxide. 5. The special effectiveness of calcium hydroxide in compounds of butadiene styrene rubber is a result of its independent structure forming ability and accelerating influence on the reaction between rubber and sulfur. 6. Magnesium oxide has a positive influence on the technical properties of rubber and on the durability of tires prepared with butadiene styrene and sodium butadiene rubbers.