Preferential positioning of γ-ray treated multi-walled carbon nanotubes in polyamide 6,6/poly(p-phenylene ether) blends

Morphological characteristics and electrical conductivity of polyamide 6,6/poly(p-phenylene ether)/multi-walled carbon nanotube (PA66/PPE/MWCNT) ternary nanocomposites were investigated. The MWCNTs were modified by ⁶⁰Co gamma ray (γ-ray) irradiation under a dry condition and O₂ atmosphere, which introduces oxygen-containing functional groups on the surfaces of the MWCNTs and thereby provides better compatibility with the hydrophilic PA66 phase. It was observed that the MWCNTs are preferentially positioned in the continuous PA66 matrix, whereas PPE domains are almost free of MWCNTs. Since PA66 consists of a continuous phase and the MWCNTs are preferentially positioned in the PA66 phase, electrical conductivity of PA66/PPE/MWCNT ternary composites is higher than that of PA66/MWCNT binary composites at the same MWCNT content. It was observed that raising the processing temperature and increasing the mixing time were effective means of improving the electrical conductivity of the composites, via enhancement of MWCNT dispersion. [Figure not available: see fulltext.]