Sustainable Thermoplastic Thermal Interface Adhesive Derived from Poly(lipoic acid) and Boron Nitride for Efficient Electronic Thermal Management.

Abstract

The escalating power density of electronics demands thermal interface materials (TIMs) that simultaneously offer high thermal conductivity, strong adhesion, and environmental sustainability. Conventional thermally conductive adhesives (TCAs) face inherent trade-offs among these properties, often relying on non-recyclable thermosets. Here, we present a sustainable thermoplastic TCA composed of a poly(lipoic acid) (polyLA)-based dynamic polymer matrix integrated with polyvinylpyrrolidone-modified hexagonal boron nitride (BN@PVP). The polyLA matrix incorporates catechol moieties and reversible Fe3+-carboxyl/catechol coordination bonds, creating a dynamically reconfigurable network. This design yields an adhesive (LD50Fe100) with high toughness (1.52 MJ m-3), and strong lap shear adhesion (884 kPa on PMMA and 1210 kPa on steel). The dynamic bonds enable room-temperature self-healing (93.1% efficiency) and robust recyclability. At a BN@PVP loading of 40 wt %, the composite (BN@LD50Fe100) achieves a thermal conductivity of 1.2 W m-1 K-1 while maintaining enhanced mechanical properties. LED chip heat dissipation experiments demonstrate a 4 °C lower operating temperature compared to devices without a TIM, with stable thermal performance over multiple cycles. This work provides a promising material strategy to overcome the traditional trade-offs in TCAs, offering a path toward repairable, reusable, and efficient thermal management solutions for advanced electronic packaging.