Solvation stabilization of vinyl chloride polymers to degradation in solution

Abstract

The rates of thermal degradation of vinyl chloride (VC) polymers in organic solvents and in the solid phase are significantly different. The kinetics of the process in the liquid phase is determined by the effects of specific and non-specific solvation interaction between the solvent and the polymer molecules. In the process of polymer degradation, solvation has different effects on the rate of random elimination of HCl from PVC with the formation of isolated CC bonds and on the formation of poly-conjugated systems of double bonds. The rates of liquid-phase degradation of VC polymers in different classes of organic solvents are mainly determined by specific polymer-solvent solvation interaction; the overall dehydrochlorination rates of VC polymers in solution increase linearly with the basicity B (donor number D N ) of a solvent: In addition to specific solvation, the rate of the liquid phase degradation of VC polymers in solvents is also affected by polymer-solvent non-specific interaction. The loosening of solvation interactions between polymer and solvent, resulting from addition of a non-polar hydrocarbon to the system, induces stabilization in solutions of VC polymers.