Chemically crosslinked flexible polymer phase change material with self-healing, self-adaptive, and shape-memory properties for thermal interface applications.

In the operation of chips and other electronic components, the inability to effectively dissipate heat to ensure high-efficiency operation has always been a problem that hinders their development. To address this issue, this paper prepares a Thermal Interface Phase Change Material (TIPCM) by melt blending paraffin wax (PW) with styrene-ethylene-butylene-styrene (SEBS) and adding dicumyl peroxide as a crosslinking agent to form and reinforce a PW-SEBS crosslinked network. TIPCM maintains its structural integrity even above the melting temperature of PW due to the chemically crosslinked SEBS network, solving the leakage problem of phase change materials. Moreover, the material possesses self-healing capabilities, with the degree of self-healing reaching up to 70 % of its original state. Boron nitride (BN) is added as a thermally conductive filler, which increases the thermal conductivity of the TIPCM by 348.14 %, meeting the high thermal conductivity requirements of thermal interface materials. After the addition of the ceramic material BN, the TIPCM still possesses flexible characteristics and its tensile break elongation rate is as high as 129.1 %. Its adaptive capability allows it to better conform to the surfaces of various components to reduce contact thermal resistance. The TIPCM exhibits excellent thermal management performance for chips, reducing the temperature of the simulated CPU to 51 °C and 66 °C at 4 V and 5 V, respectively, when used in conjunction with a radiator. This significantly reduces the adverse effects of contact thermal resistance and provides a new option for chip thermal management applications.