Relaxation of polystyrene rubbed at low temperature

Fast relaxations of polystyrene, a significant drop of optical birefringence with order of second (~23s), below its glass temperature were studied in this thesis. Results showed that those birefringence drops are around 30x10-6 and similar results were gotten in various molecular weights of polystyrene (18.1kg/mol to 442kg/mol) and temperatures (-10°C to 20°C). However, distributions of such drops were wider at low experimental temperature. Also, saturated normalized birefringence of polystyrene is high when it is rubbed under low temperatures. In order to discover above outcomes, Reflectance Difference Spectroscopy (RDS) was employed to have real-time monitoring. Besides, double way rubbing system and low temperature plus dry experimental environment was developed to carry out experiments, which different samples were rubbed by velvet cloth under various conditions