Stabilization of poly(vinyl chloride) with preheated metal stearates and costabilizers. II. Use of a polyol

Continuing with the evaluation of costabilizers along with preheated metal stearates to stabilize poly(vinyl chloride) (PVC), pentaerythritol was chosen as a long-term costabilizer. During normal stabilization conditions, the polyol enhances the induction time to degradation but produces large amounts of polyenes. The use of the preheated mixture of metal soaps and preheated ZnSt2 enhanced even more such times, while preheated CaSt2 reduced them. The same effect was seen with the β-diketone; and, as in that case, the results seems to be the sum of both separated effects. Evaluations of induction times to degradation, carbonyl formation, visible reflectance, and UV-visible and fluorescence spectroscopic techniques support these findings.