Abstract

Polyhedral oligomeric silsesquioxanes (POSS) and γ-glycidoxy propyl trimethoxy silane (KH560) were applied to modify boron nitride (BN) and boron nitride whisker (BN_w), and modified BN (m-BN) and modified BN_w (m-BN_w) were added as thermally conductive fillers to polybenzoxazine (PBz) matrix to synthesize m-BN/m-BN_w/PBz composite by hot press. The research results indicate that the modification of BN and BN_w and the synergistic effect between m-BN and m-BN_w can significantly improve the thermal conductivity of PBz composite. The thermal conductivity of PBz composite with 25 wt % m-BN and 25 wt % m-BN_w reached to 1.27 W/mK, which is 35% higher than PBz composite with 50 wt % m-BN (0.94 W/mK), 76% higher than PBz composite with 50 wt % BN (0.72 W/mK), and also display excellent electrical insulation performance. The corresponding dielectric constant (ε) and dielectric loss (tan δ) were 3.83 and 0.0078, respectively. Besides, the T_{heat-resistance index} (T_HRI) of PBz composite with 25 wt % m-BN and 25 wt % m-BN_w is 242.26 °C, and the thermal degradation temperature at 30% weight loss (T₃₀) is 557.72 °C, are higher than PBz matrix (224.46 and 498.88 °C). And the tensile strength of PBz composites with 25 wt % m-BN and 25 wt % m-BN_w is 47.71 MPa.

摘要

应用多面体低聚倍半硅氧烷（POSS）和γ-环氧丙氧基丙基三甲氧基硅烷（KH560）改性氮化硼（BN）和氮化硼晶须（BN _w），以及改性BN（m-BN）和改性BN _w（m-BN）_w ) 作为导热填料添加到聚苯并恶嗪 (PBz) 基体中，通过热压合成 m-BN/m-BN _w /PBz 复合材料。研究结果表明，BN和BN _w的改性以及m-BN和m-BN _w之间的协同作用可以显着提高PBz复合材料的热导率。含25 wt % m-BN和25 wt % m-BN _w的PBz复合材料的热导率达到 1.27 W/mK，比含 50 wt% m-BN (0.94 W/mK) 的 PBz 复合材料高 35%，比含 50 wt% BN (0.72 W/mK) 的 PBz 复合材料高 76%，并且还显示优良的电绝缘性能。相应的介电常数 (ε) 和介电损耗 (tan δ) 分别为 3.83 和 0.0078。此外，含有25 wt% m-BN和25 wt% m-BN _w的PBz复合材料的T_耐热指数（T _HRI）为242.26 °C，30%失重时的热降解温度（T ₃₀）为557.72 °C，高于 PBz 矩阵（224.46 和 498.88 °C）。含有25 wt% m-BN和25 wt% m-BN _w的PBz复合材料的拉伸强度为47.71 MPa。