Mechanism of Organotin Stabilization of Poly(vinyl Chloride).6.Compatibility of Organotin Stablizers With PVC

摘要

Compatibility of PVC with liquid alkyltin alkylthioglycolate stabilizers was studied by thermal methods,including isothermal calorimetry of mixing,DSC,DMA,and dielectric relaxation.The enthalpy of mixing of PVc with the series of alkyltin alkyl thioglycolaes was measurec over the entire concnetration range at ambient conditions.It was found that all tested compounds are compatible with PVC in a broad concnetration range and form homogeneous mixtures.The results are discssed in terms of the superosition of glassy state and molecular interaction contributions to the enthalpy of mixing of the glasy polymer with liquid additives.The influence of organotin stabilizers on the glassy structure of PVC films was studied by means of organotin stablizers on the galssy structure of PVC films was studied by means of DSC and the dielectric relaxatio spectrum.The enhancement of the galssy structure of PVC by alkyltin alkyl thioglycolates is interpreted as the result of strong multi-site molecular complexes between organotin molecules and PVC chains,which act as additional clips in the entanglement network of polymer chains.