▎ 摘　　要

The low thermal conductivity coefficient (lambda) of polyimide (PI) films are limiting their application in high-power electronic equipment, and the disordered alignment of fillers discourage efficient improvement of lambda for PI-based composite films. Herein, polyethylene glycol trimethylnonyl ether is used to perform liquid crystalline modification on graphene fluoride (LC-GeF) to achieve ordered alignment. Intrinsically thermally conductive liquid crystalline PI (LC-PI) matrix is utilized to fabricate thermally conductive LC-GeF/LC-PI composite films. In-plane lambda (lambda(parallel to)) and through-plane lambda (lambda(perpendicular to)) of 15 wt % LC-GeF/LC-PI composite films reach 4.21 and 0.63 W/(m.K), 446.8% and 320.0% higher than lambda(parallel to) (0.77 W/(m.K)) and lambda(perpendicular to )(0.15 W/(m.K)) of normal PI films, 99.5% and 96.9% higher than lambda(parallel to) (2.11 W/(m.K)) and lambda(perpendicular to) (0.32 W/(m.K)) of LC-PI films, also higher than 15 wt % GeF/LC-PI composite films. Additionally, LC-GeF/LC-PI composite films possess more excellent insulating, mechanical, and thermal properties than GeF/LC-PI composite films.