Isothermal Relaxation of Rubbed Polystyrene Thin Films Probed with Optical Birefringence Measurements

Optical birefringence measurements were used to observe the isothermal relaxation of rubbed polystyrene films on silica substrates below the glass transition temperature. The relaxation dynamics were described by the Kohlrausch–Williams–Watts relaxation function with Arrhenius temperature dependence on relaxation time. The isothermal results were in good agreement with results obtained using a 1 K min −1 heating rate.