OZONIZATION, A MINOR ROUTE FOR ELASTOMER WEATHERING

The main oxidation products formed in the weathering, the artificial photoageing and the low temperature thermoageing of butadiene and isoprene rubbers are determined by FTi.r. spectrophotometry and compared to the products of exposure to ozone. The kinetic evolution of these different oxidative reactions are determined too. Both spectral and kinetic differences allow to ensure that the ozone tests are not able to predict the long term behaviour of these elastomeric materials used in outdoors conditions. Experiments were carried out both on unmodified polymers and on polymers containing 2 and 45% w/w of carbon black and vulcanized by sulphur/CBS, peroxide and electron beam. Only some kinetic differences were detected according to the vulcanization mode.