In-situ construction of dense thermal conduction networks endow the polymeric composites with advanced thermal management capability and superior dielectric properties

A multiscale BN modulation strategy for preparing dense thermal conductive networks of polymer composites and decreasing simultaneously the interface thermal resistance is demonstrated. The composites show high thermal conductivity (κ = 1.957 W m −1 K −1 ) promoting the κ of neat polymer by ∼9 times, and showing a relatively high κ enhancement (∼800%). In addition, the interface thermal resistance decreased by ∼25% compared to that of conventional mixed systems. • A novel strategy to prepare functional polymeric composites is proposed. • Composites show low interfacial thermal resistance and high thermal conductivity. • More efficient fillers interconnection formed dense thermal conductive networks. • Endowing composites with superior dielectric properties by synthetic active esters. Developing high-performance thermal management materials with continuous thermal conductive networks (TCN) and low interface thermal resistance (ITR) remains challenging for heat dissipation of modern electronics. Here, a multiscale BN modulation strategy for preparing dense TCN of polymer composites and decreasing simultaneously the ITR is demonstrated. As a result, the composites in this system show further thermal conductivity (κ) enhancement (25.1%) compared with single kinds of filler systems, promoting the κ of neat polymer by ∼9 times (1.957 W m −1 K −1 ), and showing a relatively high κ enhancement (∼800%). Based on the experimental and theoretical simulation results, the ITR decreased by ∼25% compared to that of conventional mixed systems, which is in accordance with κ enhancement results, indicating this method can enable efficient interconnection of fillers and dense TCNs. Meanwhile, it also presents superior dielectric properties (the dielectric constant and loss are 3.17 and 0.018, respectively.) and thermal stability (char yield is up to 72.70%, T HRI is >269 °C.). This work provides valuable guidance for designing efficient TCN in composites and demonstrates their potential application in electronic packaging and thermal management of electronics.