Polyurethane composite films with self-assembled graphene fluoride: Constructing conductive pathways for thermal management with electrical insulation

Abstract

Polymer composites incorporating carbon-based fillers have been demonstrated to have high thermal conductivity (TC), yet their high electrical conductivity restricts their utility in electronic devices. As a solution to this issue, we report graphene fluoride (GF) incorporated thermoplastic polyurethane (TPU) composites that are both thermally conductive and electrically insulating. The TPU composites, engineered for both high TC and electrical insulation while maintaining flexibility, were fabricated using a combination of electrospinning, dip-coating, and hot-pressing techniques. This study aimed to investigate the effects of various dip-coating cycles on the in-plane thermal conductivity (λ∥) of GF@TPU composites. Noticeably, GF@TPU composites exhibited an outstanding TC, reaching up to 13.5 W m−1 K−1 with 10 vol% GF loading, marking a 75-fold increase compared to the neat TPU films. Moreover, the GF@TPU composites exhibited an electrically insulating property of 6.5 × 1010 Ω/m. This work provides a promising strategy to make thermally conductive composites with electrical insulation for thermal management in smart electronics.