Effects of azodicarbonamide and vulcanization methods on acrylonitrile-butadiene rubber/polyvinyl chloride foam properties

Abstract

Effects of azodicarbonamide (ADC) and vulcanization method, that is, hot air (HA) and infrared (IR), on acrylonitrile-butadiene rubber/polyvinyl chloride (NBR/PVC) foam properties were investigated. Results reveal that ADC content had no significant influence on the onset of vulcanization. The cure pattern of the compounds was dependent on ADC content. Foam density was reduced, whereas water absorption and compression set were increased with increasing ADC content. Regardless of the vulcanization method, the blowing agent utilization efficiency was increased slightly, whereas the thermal conductivity was decreased with increasing ADC content up to 50 phr and then leveled off. At any given ADC content, the vulcanization method had no significant effects on both foam density and porosity. Compared with HA vulcanization method, IR vulcanization method gave slightly lower thermal conductivity but greater values of water absorption and compression set. Foam structure was used to explain the results.