INVESTIGATION OF THE INFLUENCE OF WHITE FILLERS ON THE FORMATION OF N-NITROSAMINES IN RUBBER COMPOUNDS

During the past two years, major manufacturers of white fillers have c ooperated within the framework of the Committee ''Analytical Working G roup White Fillers/N-Derivates'' In a comprehensive investigation conc erning the influence of commercial white fillers on the formation of N -nitrosamines in rubber compounds, The whole range of surface areas wa s taken into account. The fillers were analyzed for their N-nitrosamin e content, and the amount of NO(x) bound to the filler surface by adso rption. Their nitrosating potential was determined by reacting the nit rosating substances with dimethylamine. In addition, the N-nitrosamine concentration of an EPDM compound, with 50 phr filler and without fil ler, containing tetramethylthiuram disulfide as accelerator was determ ined by extraction of the vulcanizates with methanol and by analysis o f the gas phase. This study furthermore investigates the influence of storage time and conditions of fillers and vulcanizates on the N-nitro samine concentration.