Polymer, Vol.41, No.3, 1077-1086, 2000
Uniaxial drawing behavior of syndiotactic polystyrene
The drawing behavior of syndiotactic polystyrene (sPS) has been studied in the temperature range around its glass transition. Amorphous sheets have been prepared by quenching, and drawn at temperatures from 90-120 degrees C. The development of orientation and crystallization has been examined using the optical birefringence method, standard thermal analysis, and X-ray diffraction. The effect of draw ratio, draw rate, and draw temperature on orientation and crystallinity were examined. Deformation dependent crystallization and orientation have been observed. Both orientation and crystallinity increase with increasing draw ratio and draw rate, but decrease with increasing draw temperature in the temperature range of 90-114 degrees C. These results can be explained according to the competition between deformation and relaxation of molecular chains during drawing. Results show that crystallization of sPS is predominantly controlled by stress rather than by temperature during drawing in the temperature range of 90-114 degrees C.