Enhancement of polyvinyl chloride (PVC)/epoxidised natural rubber (ENR) blend properties by electron beam irradiation f effect of antioxidants

摘要

The effects of 3 different types of antioxidants; a hindered phenol, a phosphite and a hindered amine light stabilizer (HALS) on the radiation-induced crosslinking and oxidative degradation of 70/30 polyvinyl chloride (PVC)/epoxidised natural rubber (ENR) blend with a crosslinking agent were studied. The gel fraction, tensile strength, elongation at break, modulus and hardness were used to follow the irradiation-induced crosslinking and oxidative degradation of the blend. Results on mechanical properties implied that the hindered phenol is an effective antioxidant for the investigated PVC/ENR blend system. The modulus and hardness results revealed that addition of antioxidant to the blend favours the formation of free ends in the crosslinked network upon irra- diation. The Fourier transform infrared spectroscopy analysis indicated that the radiolysis products of hindered phenol at 60 kGy induce post irradiation reaction in PVC/ENR blends. However, studies did not reveal the exact nature of the radiolysis product responsible.