One-Component Degradable High-Thermal-Conductivity Liquid Crystal Epoxy Resins and Their Composites Based on Self-Curing Strategy

Abstract

High thermal conductivity liquid crystal epoxy resins (LCERs) and their composites are essential for efficient thermal management in electronic devices. The production of LCERs currently depends on combining epoxy monomers and hardeners or catalysts. However, these curing agents or catalysts destroy the liquid crystal phase in the crosslinked network, thereby limiting the thermal conductivity of LCERs. Here, a novel self-curing strategy is developed by incorporating a Schiff base into liquid crystal epoxy monomers, enabling the curing of monomers without additional agents or catalysts. This self-curing method effectively retains the ordered liquid crystal phase in the LCERs. Therefore, the self-cured LCEP-SC resin achieves a thermal conductivity of 0.36 W mK⁻¹, 133% higher than amine-cured LCEP-DDM, ≈1.8 times higher than that of general bisphenol A epoxy resin (E51-DDM, 0.2 W mK⁻¹). LCEP-SC-BN composites with 10 wt.% BN further exhibit a thermal conductivity of 0.61 W mK⁻¹, surpassing LCEP-DDM-BN composites by 42%. Additionally, the dynamic Schiff base structure allows LCERs degradation in acidic DMF/water solutions, enabling efficient recovery of BN fillers. This self-curing strategy provides a sustainable pathway for developing high thermal conductivity LCERs and their composites, offering enhanced thermal conductivity and recyclability for advanced electronic applications.