Optimized Interface Structure of Degradable Epoxy Composites Based on the Self-Assembly of Lignin-Graphite for Thermal Management Application
Haohan Wu, Yingchun Liu, Liheng Chen, Zhengwen Li, Zhaosong Hu, Xuliang Lin, Xueqing Qiu
Abstract
Enhancing the interface compatibility between the polymer matrix and filler is still a hotspot issue for the fabrication of thermal management materials. In this work, biomass lignin was used innovatively as coupling reagents to optimize the interface microstructure of the matrix/filler. The as-prepared lignin-graphite (AL@GP) and epoxy resin with a Schiff base structure (PBD-EP) were employed as functionalized filler and polymer matrix, respectively. And a degradable and thermally conductive epoxy composite was prepared through the hot-press technique. Experimental and theoretical calculations results based on the first principles demonstrated enhanced interface bonding between GP and PBD-EP. Besides, the developed polymeric composites exhibited excellent thermal conductivity (2.852 W m –1 K –1 ) when loaded with 50 wt % AL@GP, increasing by 26.1% compared with the PBD-EP/GP system. Moreover, it presented a reduced interface thermal resistance (0.10745 m 2 K W –1 ) and superior solvent-free green degradability. LED heat dissipation experiments indicated the potential of as-prepared composites for thermal management applications. This work not only provides a novel and facile filler functionalization strategy for improving the interfacial interaction of the matrix/filler but also promotes the high-value applications of biomass lignin.