Lutidine catalyzed highly thermal conductive graphite polyimide films via controlling grain size

Abstract

Huge damage to high-power equipment may be caused by local overheating. In order to solve this problem, in this work, two isomeric lutidines were used as organic base catalysts to prepare polyimide(PI) films. After carbonization and graphitization, graphite PI films with high thermal conductivity were obtained by growing intrinsically without any other materials. Different lutidines catalysts are both beneficial to highly oriented graphite PI films preparation. Lattice growth of graphite PI films can be promoted by an appropriate amount of catalyst. The thermal conductivity was affected by catalyst type and its alkalinity. Graphite film catalyzed by 3,5-lutidine is more outstanding. Among them, the grain size of graphite film prepared with 3,5-lutidine at a concentration of 3.0 wt% is the largest (95.76 nm). This film with the lowest defect (2%) and high ratio of sp2-hybridized carbon (84%), showed the highest thermal conductivity (1483 W/(m∙K)), representing a more than 3–64 times improvement over pure PI film graphited in other methods. Graphite PI film prepared by choosing different lutidines to control the grain size shows great potential for thermal management, which provides a new idea for solving heat dissipation.