Impacts of polyketone-grafted carbon nanotube on the thermal, mechanical, and electromagnetic shielding performance of polyketone composites

Abstract

We report the impacts of polyketone-grafted multiwalled carbon nanotube (CNT-g-PK) on the thermal, mechanical, electrical, and electromagnetic interference (EMI) shielding performance of polyketone (PK) composites. For this purpose, a masterbatch of 10 wt% hydroxylated CNT (CNT-OH) with 90 wt% glycidyl methacrylate-grafted PK (PKGMA) is manufactured by solution mixing and drying. It is then composited with neat PK to fabricate a series of PK/CNT-g-PK composites with varying CNT amounts of 0.5–5.0 wt% via reactive melt-compounding. Infrared spectral results confirm the successful formation of CNT-g-PKs in the melt-compounded composites through the reaction between the hydroxy group of CNT-OH and the epoxy group of PKGMA. Electron microscopic images of PK/CNT-g-PK composites reveal that CNTs are evenly distributed and tightly encapsulated in the composite matrices, indicating good interfacial adhesion between the reinforcing CNT filler and the PK matrix. Accordingly, the melt-crystallization temperature of the PK/CNT-g-PK composites increases as the CNT content increase owing to the nucleating agent role of CNTs, while the melt-crystallization/melting enthalpies decrease due to the mobility hindrance in the PK chains anchored by CNTs. The elastic storage modulus and tensile strength of PK/CNT-g-PK composites are significantly enhanced with increasing CNT content. The 1-mm-thick PK/CNT-g-PK composite with 5.0 wt% CNT exhibits high electrical conductivity of 6.98 × 10−4 S/cm and EMI shielding effectiveness of ∼22.4 dB in the X-band radio frequency range.