Lin Chia-Min, Chen Chien-Han, Lin Ching-Hsuan, Su Wen Chiung, Juang Tzong-Yuan
Department of Chemical Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
Chung Shan Institute of Science and Technology, Lungtan, Tauyuan 32546, Taiwan.
ACS Omega. 2018 Apr 18;3(4):4295-4305. doi: 10.1021/acsomega.8b00256. eCollection 2018 Apr 30.
To achieve high- and low-dielectric epoxy thermosets, four dicyclopentadiene-derived polyarylates (26-P, 26-M, 236-P, and 236-M) were prepared from 2,6-dimethyl (or 2,3,6-trimethyl) phenol-dicyclopentadiene adduct with terephthaloyl (or isophthaloyl) chloride by high-temperature solution polymerization. The resulting polyarylates, exhibiting active ester linkages (Ph-O-(C=O)-) are found to be reactive toward a commercial dicyclopentadiene phenol epoxy (HP7200) in the presence of some lone-pair electron-containing compounds. Five compounds including 4-dimethylaminopyridine (DMAP), imidazole, 2-methylimidazole, triphenylphosphine, and triphenylimidazole have been evaluated as a catalyst for the curing reactions. We found that DMAP, with the smallest p among them, is the best catalyst according to differential scanning calorimetry, infrared, and thermal analyses. The thermal and dielectric properties of the polyarylate/HP7200 thermosets are evaluated. We found that they exhibit a high characteristic (e.g., is 238 °C for DMAP-catalyzed, 236-P/HP7200 thermoset). Furthermore, because of the hydrophobic methyl and cycloaliphatic moieties, and the secondary hydroxyl-free structure, polyarylate/HP7200 thermosets show a relative low-dielectric constant of around 2.75 U. The detailed structure-properties relationship is discussed in this work.
为了制备高介电和低介电环氧热固性材料，通过高温溶液聚合，由2,6-二甲基（或2,3,6-三甲基）苯酚-二环戊二烯加合物与对苯二甲酰氯（或间苯二甲酰氯）制备了四种二环戊二烯衍生的聚芳酯（26-P、26-M、236-P和236-M）。发现所得的具有活性酯键（Ph-O-(C=O)-）的聚芳酯在一些含孤对电子的化合物存在下对市售二环戊二烯苯酚环氧树脂（HP7200）具有反应性。已评估了包括4-二甲氨基吡啶（DMAP）、咪唑、2-甲基咪唑、三苯基膦和三苯基咪唑在内的五种化合物作为固化反应的催化剂。我们发现，根据差示扫描量热法、红外光谱和热分析，其中p值最小的DMAP是最佳催化剂。对聚芳酯/HP7200热固性材料的热性能和介电性能进行了评估。我们发现它们表现出高玻璃化转变温度特性（例如，对于DMAP催化的236-P/HP7200热固性材料，玻璃化转变温度为238℃）。此外，由于疏水性的甲基和脂环族部分以及无仲羟基结构，聚芳酯/HP7200热固性材料显示出相对较低的介电常数，约为2.75。本文讨论了详细的结构-性能关系。
