Tin oxide cross-linking of chloroprene rubber
Polimery 2015, No 3, 186
A new method of cross-linking chloroprene rubber (CR) with tin oxide (SnO) is presented. From the viewpoint of the mechanical properties, the optimal SnO contentis between 1 and 2 phr of CR (Table 1, Fig. 1), i.e. definitely less than the amount of ZnO and MgO typically used in CR cross-linking. CR vulcanizate curedwith tin oxide demonstrates significantly higher tensile strength than CR cross-linked using a conventional mixture of ZnO and MgO. The determined values of equilibriumvolume swelling and Mooney-Rivlin elasticity constants indicate a greater number of intermolecular cross-links. It was found that the incorporation of silica or carbon black into CR leads to an increase in the tensile strength of the vulcanizatecrosslinked with 1 phr SnO (Table 2). Although the addition of kaolin to CR cured with SnO results in a slight decrease in the mechanical properties of vulcanizates, it causes a marked reduction of their flammability, as indicated by increase in the oxygen index value (Fig. 2).