Studies on the Nature of the Action of Organic Accelerators of Vulcanization. The Action of Organic Accelerators on Rubber Sols I–III

Abstract

Abstract While there is a difference of opinion as to the exact mechanism involved, it is generally agreed that the action of organic accelerators in hastening the vulcanization process is usually attributed to the conversion of the sulfur into an active form, probably through the intermediate formation of a compound capable of yielding “nascent” sulfur. But some workers, (Ames, J. Soc. Chem. Ind., 43, 117T (1924); Kirchhof, Kolloid-Z.,, 14, 35 (1914); Twiss, J. Soc. Chem. Ind., 35, 782 (1917); Ditmar, Z. angew. Chem., 34, 465 (1921)) have suggested that the action of organic accelerators might be on the rubber hydrocarbon itself. This theory has not been generally developed, though it has received some small amount of evidence through the works of Le Blanc and Kröger (Z. Elektrochem., 27, 335 (1921)) and Naunton (J. Soc. Chem. Ind., 44, 243T (1925)). These investigators found that the viscosity of rubber solutions decreased with the introduction of an organic accelerator, and referred this phenomenon as a “depolymerization” of rubber. These observations possibly suggest that the influence of accelerators is exerted upon the rubber and constitute the only direct evidence in favor of this view.