For monitoring the elastic and viscous behavior of the copolymers under fluctuating load, dynamic mechanical thermal analysis (DMTA) was carried out with a DMA Q800 apparatus (TA Instruments, New Castle, Delaware, USA). The sample films were prepared with 0.5mm of thickness and examined in tension mode over a temperature range from -100 to 150 °C with a heating rate of 3 °C/min and 1 Hz frequency.