The influence of CNT film on the mechanical and electrothermal properties of thermoplastic CF/PPS composites

This study investigated the impact of CNT film as functional interlayer on the mechanical and electrothermal properties of carbon fiber reinforced polyphenylene sulfide (CF/PPS) composites. Composites with varying interlayer structures were fabricated via vacuum hot-pressing. Microstructural characterization showed that PPS resin fully infiltrated CNT film micropores, forming strong interfacial bonding. The embedded CNT film also enhanced mechanical properties of the composites. Compared to CF/PPS, the tensile, compressive, and flexural strengths of CF/CNTs/PPS composites were enhanced by 6%, 6%, and 10%, respectively, while the interlaminar shear strength remained unaffected. The microscopic orientation of carbon nanotube bundles is characterized by the distribution along the horizontal direction within the plane. Thus, the in-plane oriented CNT film effectively inhibited crack propagation and provided additional load transfer paths during tensile, compressive, and bending deformations, but exhibited limited reinforcement in the through-thickness direction during shear. Additionally, the embedded CNT film endowed the composites with excellent electrothermal performance, including rapid response, uniform in-plane temperature distribution, and long-term stability, with the CNT film structure well preserved after hot-pressing. This study provides a novel approach for fabricating electrothermal-functional thermoplastic composites.