ANNEALING OF THE DELTA-FORM OF SYNDIOTACTIC POLYSTYRENE

The effects of thermal treatments on the phase organization in some po lymorphic forms of syndiotactic polystyrene have been investigated. in particular the thermal stability of the delta form was studied using x-ray diffraction and infrared spectroscopy as analytical techniques. The obtained results show that this form, characterized by chains in h elix conformation, is affected by nonequilibrium phenomena. Moreover, the transition from the delta to the gamma form occurs through an inte rmediate form which maintains the helix chain conformation but partial ly loses the crystalline order.