Mechanically strong, reprocessable and thermally stable PDMS/Hexagonal boron nitride composites with desirable thermal conductivities based on dynamic silyl ether linkages

Abstract

Reprocessable thermally conductive polymer composites with excellent thermal management performance have become the research hotspot in order to solve the heat dissipation problem of electronic devices and reduce waste of resources. Herein, efficiently reprocessable PDMS/hexagonal boron nitride (h-BN) composites with excellent mechanical properties, thermal stability and desirable thermal conductivity were designed and prepared based on dynamic silyl ether linkages. The tensile strength and toughness of the composites with h-BN content of 28.6 wt% can reach 4.79 MPa and 23.3 MJ/m3, respectively. Moreover, the thermal conductivity of this composites increased by 4.63 times to 0.659 W m−1 K−1 with respect to that without h-BN. More importantly, the reprocessing efficiency of PDMS elastomer can be as high as 100% and is capable of achieving over 94% at containing 28.6 wt% h-BN, mainly due to the intramolecular catalysis of tertiary amine group at the γ-position of silyl ether. Further, the intrinsic excellent heat resistance of matrix is successfully retained and the composites show good adhesion properties on different substrate materials and insulating properties. In a word, the composites with excellent comprehensive performance pave the way for the development of thermal management materials in the modern electronics industry.