A study on the mechanism of polyvinyl chloride stabilization by lead salts

Infrared spectroscopic and DTA measurements and chemical analysis have shown that during stabilization of PVC with organic and inorganic basic lead salts various reactions occur: (a) binding of the evolved HCl, by these salts with the formation of lead chloride and complexes, including HCl, which catalyze the PVC degradation; (b) complex-forming reaction with the reactive PVC groups, which decreases the intensity of color of the polymer. In addition, with weak-organic-acid basic lead salts, exchange of labile Cl atoms for acid residues in PVC occurs, which results in an increase in inherent polymer stability.