Functionalization of graphite via Diels-Alder reaction to fabricate poly (vinyl alcohol) composite with enhanced thermal conductivity

Surface modification of filler is often utilized to effectively reduce interfacial thermal resistance in thermal conductive materials. In this work, pristine graphite was modified via Diels-Alder reaction with acrylic acid to improve the inertness of graphite (AA@G). FT-IR, Raman and XPS confirmed the reaction onto the surface of graphite. A series of poly (vinyl alcohol) composite loaded with AA@G and graphite was fabricated to investigate the interfacial interaction between matrix and filler. Both XRD and DSC showed that introducing of AA@G would decrease crystallinity of PVA matrix in composite, providing convincing evidence of strong interfacial interaction. Owing to the excellent interfacial interaction, the maximum TC of composite loaded with 30 wt% AA@G reached to 21.3Wm(-1) K-1, which was 44% higher that of composite loaded with the same mass fraction of graphite (14.1Wm(-1) K-1). With the synergistic increment in thermal conductive performance, AA@G exhibited extremely high enhanced efficiency of 358% compared with other literature. Also, good thermal stability makes AA@G potential in thermal management system and flexible electronics.