▎ 摘　　要

NOVELTY - Modifying graphite powder comprises (i) performing plasma etching pretreatment on graphite powder to obtain pretreated graphite powder; (ii) subjecting pretreated graphite powder to hydroxylation treatment to obtain hydroxylated graphite powder; and (iii) completely hydrolyzing coupling agent in solvent, and adding hydroxylated graphite powder for graphite powder modification. USE - The powder useful for preparing polyolefin-based graphite orientation-type thermal interface material (claimed). ADVANTAGE - The material has stable performance, high degree of orientation, density and thermal conductivity, and good flexibility and resilience. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) modified graphite powder, prepared as mentioned above; (2) polyolefin-based graphite orientation type thermal interface material, comprising polyolefin matrix, modified graphite powder, and a filling type heat conducting filler, where the filling-type heat conducting filler is particle, whisker, fiber, or nanowire filler with a micrometer size or a nanometer size; and (3) preparing polyolefin-based graphite orientation type thermal interface material, comprising (a) mixing and stirring polyolefin matrix, modified graphite powder, filling-type heat conducting filler to obtain mixed material, (b) performing orientation treatment to the mixed material to obtain lamellar mixed material, (c) freezing the lamellar mixed material to obtain frozen lamellar mixed material, (d) maintaining the frozen state of the frozen lamellar mixed material, cutting the frozen lamellar mixed material to obtain a layered sample of the specified width and length, and subjecting the layered sample to laminating treatment, (e) using vacuum pressure to process the laminated sample, and slowly increasing the temperature during the process, so that the mixture changes from a solid state to a viscous fluid state, and a compacting sample to obtain perform, (f) carrying out high-temperature curing treatment on the dense sample preform to obtain a cured sample, and (g) cutting the cured sample in the direction perpendicular to the thickness of the layered sample.