Flexible phase change composite films with improved thermal conductivity and superb thermal reliability for electronic chip thermal management

• Phase change microcapsule (MPCM) with enthalpy of 192.9 J/g and encapsulation ratio of 94.5% has been prepared. • Flexible phase change composite films based on MPCM, MWCNT, BN and SEPS were constructed by solution casting. • The obtained composite film has improved thermal conductivity and superb thermal reliability. • The composite films own an outstanding thermal management capacity. High-performance flexible composites with excellent thermal management ability are essential to dissipate the heat generated in electronic systems. Herein, micro-encapsulated phase change material (MPCM) with n-Docosane core and MF resin shell is prepared. The obtained MPCM exhibits large phase change enthalpy (192.9 J/g). Subsequently, flexible composites are prepared by incorporating the MPCM, multi-walled carbon nanotubes (MWCNT) and hexagonal boron nitride (h-BN) in styrene-ethylene-propylene-styrene (SEPS) polymer matrix. At 30 wt% MPCM, the phase change enthalpy of 60.6 J/g is achieved. 3wt%MWCNT/10wt%h-BN/30wt%MPCM composites show improved thermal conductivity of 0.44 W m -1 K -1 , which is 95.5% higher than pure SEPS. The composites are applied in chip for thermal energy dissipation, the temperature of chip’s lower surface is only 62.6 o C, which is 22.84% lower than pure SEPS. Overall, the MWCNT/h-BN/MPCM composites with superior thermal properties and mechanical characteristics are promising in the field of electronic equipment thermal dissipation.