Influence of copper chloride and potassium iodide mixture in poly(vinyl chloride) exposed to gamma irradiation

Samples of commercial PVC containing a salt mixture of CuCl2/KI (PVC-salt) were investigated. The samples were irradiated with gamma radiation (60Co) at dose 25 kGy. PVC and PVC-salt system showed a decrease in viscosity molar mass values on irradiated samples reflecting the main chain random scissions effect. However the PVC-salt at 0.5 wt% concentration showed no significant degradation index value. This result suggests that salt keeps the good radiolytic stabilization behavior of gamma-irradiated PVC. The CuCl2/KI mixture at 0.5 wt% in the PVC matrix also influenced the thermal behavior of the polymer increasing the maximum thermal degradation temperature in 42 °C. In addition, the salt mixture influences significantly the Young's Modulus of PVC increasing the rigidity of polymer. Specific interactions between PVC and CuCl2/KI mixture were observed in the FT-IR spectra.