PVC modification with new functional groups. Influence of hydrogen bonds on reactivity, stiffness and specific volume

The chemical modification of PVC with new bifunctional thiol compounds is reported. Aliphatic as well as aromatic reactives were tested and the influence of protic and non-protic functionalities on reactivity was studied. The chemical structure of the polymers was analyzed using ¹H NMR spectroscopy.The structural changes in the modified samples were monitored by means of density and T_g determinations, which are a measure of interchain spacing and chain stiffness. While protic functionalities lead to polymers with strongly enhanced T_g values indicating a considerable stiffening of the system due to physical interaction by hydrogen bonds, the softening-point temperature of PVC modified with non-protic substituents does not change very much.The interchain spacing of the polymer is not significantly altered by the presence of mobile hydrogen in the polymer.