Stabilization of poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends

摘要

In order to improve the positive effect of irradiation, the stability of poly (vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends was studied with particular attention to stabilization of the PVC phase. Stability of 70/30 PVC/ENR blends was studied by examining evidence from brabender torque-time curves, tensile strength, yellowness index, hardness and gel fraction. The observa- tion on the trend shown in the above properties has confirmed that among the common PVC stabilizers employed in this studies, tribasic lead sulfate is efficient in stabilizing PVC/ENR blends as well as enhancing the blend properties upon irradiation. Addition of zinc octoate proved to play a major role in providing good color retention and radiation stability to the blends although the improvement on the blend properties through irradiation was found to be relatively low. Studies also revealed that the initial sta- bility of the blend during processing is of prime importance in order to further stabilize the blends upon irradiation. Possible sta- bilization of the blends by oxirane group present in ENR is also discussed.