2.5. Dynamic Mechanical Analysis (DMA)

The goal of DMA was to determine the impact of thermal history on the mechanical properties of E/MAA. For these tests, the polymer sheets were not heated twice during the preparation as described above. Stripes (approximately 20 mm × 3 mm) were cut from the approximately 1.6 mm thick polymer sheet, with a jaw span of 8.3 mm. Two successive runs were performed on polymer samples, starting at 25 °C. The upper temperature limit in the first cycle varied: in the first case it was 89 °C, which is near the melting start temperature of 91 °C, and in the second case it was 98 °C, which is above the melting end temperature T_m. Even at 5 °C above T_m there is still enough elastic response for the DMA to be performed, thanks to the ionic clusters in the melt. The tests were performed on the TTDMA, Triton Technology in tensile mode, with a frequency of 1 Hz, amplitude of 0.002 mm, and a heating rate of 2 °C/min.