Influence of time and temperature on deformed films of poly ether-ether-ketone (PEEK)

Amorphous films of poly ether-ether-ketone (PEEK) were drawn at 80 and 140°C up to 150% of the initial length, and analyzed immediately after the preparation, after 2 months at room temperature, and after 2 months at 120°C. X-rays, FTIR, differential scanning calorimetry were used to investigate the structural organization. Transport properties of dichloromethane vapor were used to determine the sorption in the different samples. It was found that the drawing at 80°C does not allow the crystallization, nevertheless producing an oriented sample in which a fraction of impermeable phase is present. This impermeable phase, already recognized in semicrystalline PEEK as “rigid amorphous phase”, increases its fraction with the aging time. The drawing at 140°C produces a sample with a very high impermeable phase that does not increase further with the aging time. The dimensional stability of the samples with the temperature was also investigated.