Tensile testing of the samples was performed at 25±2 °C at a crosshead speed of 500 mm min−1 according to ISO 37. The instrument used was a Hounsfield Tensometer, model H 10 KS manufactured by the Hounsfield Test Equipment Co., Ltd., UK. The dumbbell-shaped specimens, 2 mm thick, were prepared by a thermoplastic injection-molding machine with a capacity of 90 tons (clamping force) (Welltec Machinery Ltd., Hong Kong). Tension set at 100% elongation was also determined at room temperature (25±2 °C) according to ISO 2285. The samples were kept under tension for a fixed elongation and time interval then they were released from the clamp, set aside for another fixed time interval and then the changes in the sample dimensions were determined. Hardness of the samples was also measured using a Shore A type durometer according to ISO 7619.