Durability of the halogenation in synthetic rubber

Chlorination of a synthetic vulcanized styrene–butadiene rubber with 0.5 wt% trichloroisocyanuric acid (TCI) solutions in butanone was carried out. The durability of the halogenation treatment on the surface properties of rubber was assessed using contact angle measurements, attenuated total multiple reflection method (ATR-IR) spectroscopy and SEM. Adhesion was obtained from T-peel tests of treated rubber/polyurethane adhesive joints. The failed surfaces (after peel test was carried out) were characterized using ATR-IR spectroscopy. For halogenation time lower than 2 h improved wettability was obtained and the effects produced on the rubber surface were mainly due to the solvent. After 48 h, there was a high degree of surface modification and the reaction of TCI with the rubber was the dominant effect. After long periods (up to 1 year) there was evidence for the migration of the wax to the surface and for increased roughness. Therefore, although the increase in time produced a decrease in water contact angle, the peel strength is maintained high because of the chemical and morphological modifications on the rubber surface.