PHASE ORGANIZATION OF SOLVENT-CRYSTALLIZED SYNDIOTACTIC POLYSTYRENE FILMS

Sorption and diffusion of dichloromethane vapor in the helical forms- that is, delta and gamma-of syndiotactic polystyrene were investigated . The thermal transition from the delta to the gamma form occurs throu gh an intermediate mesomorphic form, also characterized by chains in h elical conformation but lacking true crystalline order. The mesomorphi c phase was found impermeable to the vapor at low activity, becoming p ermeable at higher activities. The presence of a mesomorphic phase, al ong with the crystalline and the amorphous forms, was suggested in the crystallized samples, too, and its fraction increases greatly going f rom the delta to the gamma form.