ROLE OF THE POLYMER MICROSTRUCTURE IN THE THERMOREVERSIBLE GELATION OF POLY(VINYL CHLORIDE)

Gels of polyvinylchloride (PVC) and PVC copolymers of different micros tructure and molar composition, were prepared in a series of diester-l ike solvents. The viscoelastic properties of these gels were evaluated as a function of temperature and the molecular structure was studied by small-angle neutron scattering: The degrees of proton association i n the polymer solutions were determined by H-1 NMR spectroscopy by mea suring the intensity of proton bands of CK2 monomeric units. The body of experimental data shows clearly that there is a straight relation b etween molecular structure, viscoelastic properties of the gel, degree of polymer-solvent interaction and polymer microstructure.