Hyperbranched polysiloxane junction points with dual roles in multi-crosslinked BT resin networks: Synergistic engineering of ultrahigh toughness, dielectric performance, and thermal stability

Microelectronics is rapidly advancing toward miniaturization and high-density integration. Consequently, there is a growing demand for structural-functional integrated materials with excellent comprehensive properties, particularly in cutting-edge applications like printed circuit boards. In this work, a hyperbranched polysiloxane (HBPSi) was synthesized and incorporated into a bismaleimide-triazine (BT) resin matrix. The modified bismaleimide-triazine (BT) resin features a multi-crosslinked network with HBPSi as junctions. Benefiting from the dual-role synergy of amino groups and hyperbranched architecture of HBPSi, the modified BT resin demonstrates exceptional thermal stability, significantly enhanced hydrophobicity, a low dielectric constant of 3.21 and dielectric loss of 0.016 (at 1 MHz), showing great potential for electronic applications. Based on this, the structural-functional integrated composites by incorporating aramid fiber reinforcement were fabricated. These composites not only exhibit outstanding mechanical properties (impact strength exceeding 100 kJ/m²) but also maintain excellent dielectric performance. This research establishes a simple yet effective method for manufacturing high-performance structural-functional integrated dielectric materials, thereby expanding their potential applications in next-generation electronic devices.