Effect of calcium stearates and zinc stearates on polyene formation of poly(vinyl chloride) under degradation

Abstract

The effect of calcium stearates (CaSt2) and zinc stearates (ZnSt2) on polyene formation of poly(vinyl chloride) (PVC) was investigated by gel content, ultraviolet (UV)–visible, Fourier transform infrared and static stability analyses. The linear polyene sequences are preferred to form in pure PVC and the PVC/CaSt2 mixture during degradation, and while crosslinking polyene is found in the PVC/ZnSt2 and PVC/ZnSt2/CaSt2 mixtures. The gel content increases with first high slope of 39.80 and second low slope of 7.37 in the PVC/ZnSt2 mixture. The crosslinking degree reaches 41.62%, when adding 3 phr ZnSt2. For the PVC/ZnSt2/CaSt2 mixture, the crosslinking reaction is delayed by CaSt2 because of their synergistic effect.