The dimensions of specimens were 35 ± 0.5 mm × 8 ± 0.2 mm × 2 ± 0.05 mm. DMA testing with a heating rate of 3°C/min in the 30 -250°C range, frequency of 1 Hz and amplitude of 15 µm was utilised to measure the storage and loss moduli as functions of temperature and identify the glass transition temperature. Stress relaxation experiments were conducted at five isothermal temperatures of 175°C, 180°C, 185°C, 190°C, and 195°C. The specimens were preloaded with a force of 1 mN and subsequently deformed to an applied strain of 2 % after equilibration to the desired isothermal temperature. The decay of relaxation modulus with time was recorded and the relaxation time was estimated as the time required for the modulus to drop from its plateau value by 1/e.