Study of vulcanization by radiation of polyorganosiloxane elastomers in the presence of pore forming compounds

Abstract

Studies were made of structural radiation and chemical conversions of 2.2-azo-bis-isobutyronitrile, azodicarbonamide, di-nitrozopentamethylene tetramine, benzene-sulphohydrazide (BSH) and SKT, SKTV-1, SKTFV siloxane rubbers in the presence of these “pore formers”. It was shown by EPR that pore formers † † Pore former = Porofor, a blowing agent. have a marked effect on the yield of intermediate paramagnetic reaction centres (PMC) and radiation crosslinking of the rubbers studied, however, the effect of pore formers varies and is determined by structure. It was shown that the yield of PMC in rubbers in the presence of pore formers is 5–10 times lower than the yield of crosslinks; yield increases with an increase in the amount of pore former. It was concluded that a high proportion of crosslinks are formed directly during radiolysis (at 77°K).