Enhancement of PVC/ENR blend properties by electron beam irradiation: effect of stabilizer content and mixing time

The irradiation-induced enhancement of 50/50 PVC/ENR blend was investigated with particular attention to PVC phase stabilization and Brabender mixing time. The blends which were prepared with the addition of 1-5 phr tribasic lead sulfate (TBLS) at 6 and 30 min mixing time were irradiated using a 3.0 MeV electron accelerator with doses ranging from 0 to 200 kGy. The effect of TBLS content and mixing time were studied by examining evidence from Brabender torque-time curves, tensile strength, elongation at break, modulus at 100% elongation and tan delta curves. Addition of 2 phr TBLS was found to render optimum tensile properties upon irradiation. The higher tensile properties observed for the blend obtained at 30 min mixing time reflect the importance of blend homogeneity in enhancing the irradiation-induced crosslinking. The decrease in blend heterogeneity with mixing time was evident from tan delta curves. (C) 2001 Elsevier Science Ltd. All rights reserved.