Expanded graphite thermal interface material and preparation method thereof

Abstract

The invention discloses an expanded graphite thermal interface material and a preparation method thereof. The preparation method comprises the following steps: 1) preparing expanded graphite by taking a graphite film as a raw material and adopting an oxidation intercalation method; (2) carrying out surface treatment on the expanded graphite by using a silane coupling agent to obtain modified expanded graphite; and 3) fully infiltrating the modified expanded graphite with polyolefin in a vacuum infiltration manner to obtain the expanded graphite thermal interface material. Firstly, expanded graphite is prepared by expanding a graphite film, internal network communication is good, heat conduction is facilitated, and in the process of preparing the composite material, due to overall infiltration of polyolefin, the problem of poor dispersing performance does not exist. And secondly, the expansion multiple of the expanded graphite in the preparation process is adjustable, so that the experiment is convenient to carry out. And thirdly, the bulk expanded graphite is integrally modified, so that the polyolefin is more uniformly distributed on the surface of the expanded graphite, and the purpose of controlling the infiltration amount of the polyolefin is achieved.

Description

technical field [0001] The invention belongs to the technical field of inorganic non-metallic materials, and in particular relates to an expanded graphite thermal interface material and a preparation method thereof. Background technique [0002] The rapid development of electronic devices puts forward higher requirements for heat dissipation. High thermal conductivity polymer composites are key materials for solving heat dissipation problems that arise in electronic applications. To improve the thermal properties of polymers, various fillers are used. Usually, polymers with high thermal conductivity are prepared by increasing filler loading, but high filler loading will deteriorate the mechanical properties and processing properties of the polymer matrix, limiting its application. Preparation of thermally conductive polymers with low loadings remains a great challenge. At present, a lot of work has been done on adjusting the orientation of fillers, constructing continuous...

AI Technical Summary

Problems solved by technology

2D fillers, such as graphene, tend to be horizontally oriented by simple processing, so the final composite usually shows high in-plane thermal conductivity (K ∥ ), but has limited thermal conductivity through the plane (K ⊥ )

[0003] In addition, whether the thermally conductive fillers of common thermal interface materials are metal powder or ceramic particles, there are dispersibility problems, and the filling amount is relatively large, most of which are above 60% (mass fraction)

The problem caused by poor dispersion is that the filler particles cannot effectively contact each other and cannot build a thermal conduction path, resulting in poor thermal conductivity.