Improving thermal durability and mechanical properties of poly(ether ether ketone) with single-walled carbon nanotubes

Abstract In this study, adding carbon nanotubes (CNTs) to poly (ether ether ketone) (PEEK) not only improved the mechanical properties, but also improved the thermal resistivity of PEEK owing to the CNTs’ function as an antioxidant. The PEEK–CNT composite did not show large weight loss at 450 °C. The stabilization energies (Δ G ) of CNTs for 1,4-diphenoxybenzene radical and 4-phenoxyphenol radical, which are decomposition products of PEEK at 450 °C, were calculated by density functional theory, and they were estimated to be −80.3 and 150.2 kJ mol −1 , respectively. It was confirmed that 1,4-diphenoxybenzene radical could be trapped in a high-temperature environment of 450 °C by the CNTs. The addition of CNTs yielded almost no change in formability, but the mechanical properties such as tensile strength and bending strength were greatly improved. The PEEK–CNT composite is expected to have improved heat resistivity and mechanical properties, as well as higher reliability, so that it can be used in the future in various fields such as aerospace and automotive.