The invention discloses an aluminum
oxide interface crosslinking and rubber
powder volume rejection mediated high-thermal-
conductivity ethylene propylene
diene monomer composite material and a preparation method thereof, and the preparation method is characterized by comprising the following steps: firstly, carrying out surface treatment on spherical aluminum
oxide (Al2O3) to form a stable organic
coating layer through complexation of organic
phosphoric acid and iron ions and regulation and control of reaction time and deposition environment at the same time; under the action of high-temperature shearing,
organic acid anhydride is grafted to an EPDM molecular chain to prepare anhydridized
EPDM rubber; organic modified aluminum
oxide and anhydridized EPDM are blended on a double-roller open mill, meanwhile,
zinc acetate is added to serve as a catalyst and an ionic cross-linking agent, a reversible carboxyl
ester bond is formed by
phosphoric acid hydroxyl on the surface of Al2O3 and an anhydride group on an EPDM molecular chain, and meanwhile
zinc acetate serves as an ionic cross-linking agent of
phosphoric acid and anhydride; the preparation method comprises the following steps: adding Al2O3 into an EPDM matrix, further adding
waste rubber powder and carbon nanotubes (CNTs), carrying out high-temperature
hot pressing to prepare the high-thermal-
conductivity EPDM
composite material, enabling Al2O3 and CNTs to be intensively distributed in the EPDM matrix and selectively positioned in an edge area due to the volume repulsive action of the
waste rubber powder, and bridging fillers with different dimensions to form a three-dimensional heat-conducting network, so that the heat
conductivity of the EPDM
composite material is improved. According to the structure, effective, continuous and numerous heat conduction paths can be provided,
phonon scattering is reduced, and
heat transfer is faster and more efficient. The method is easy to process and prepare and can be used in the field of electronic heat dissipation.