- 學位論文
以環境友善的製程製備聚苯醚及其衍生物
Eco-friendly Synthesis of Poly(2,6-dimethyl-1,4-phenylene oxide) Derivatives
摘要
此研究分為兩個部分，分別是以環境友善的製程製備聚苯醚(PPO)以及合成非線性結構的聚苯醚以提升其在產業上應用價值。在第一部分中，聚苯醚由2,6-二甲基苯酚(DMP)以水為溶劑氧化聚合而成，並使用由銅和新型自製的高分子配位基(衣康酸氨-丙烯酸共聚物)而成的水溶性錯合物作為催化溶劑。在聚合反應中，我們嘗試使用不同比例、分子量的單體合成高分子配位基，並測試其活性與分子量控制情形。不同濃度的銅離子、鹽酸、高分子配位基、介面活性劑等變因都已最佳化，進而得到聚苯醚的最佳產率93%(分子量=3700,分子量分佈=2.12)，產率比我們之前發表的以精胺酸(arginine)為配位基的結果72%高出許多。同時，此最佳化條件也同樣適用於二甲苯酚與2-烯丙基-6-甲基苯酚的共聚反應，且得到95%的高產率(分子量=3000,分子量分佈=2.5)，而此共聚物多了烯丙基的支鏈理應具備熱交聯特性以提升應用上的可能性。另一方面，我們也嘗試催化劑的循環使用，最後在5次的重複使用後，催化劑仍能保持一定的活性。 第二部分的實驗中，為了得到更多的交聯基並得到不同結構的聚苯醚衍生物，二甲苯酚分別與具兩個官能基的雙酚A(BPA)、具三個官能基的1,1,1-三對羟基苯基乙烷(THP)在甲醇溶劑中共聚，以形成線性結構的PPO-BPA和非線性結構的PPO-THP，而PPO也以同樣的方式聚合做為比較組。接著，比較和探討各高分子的黏度、分子大小、玻璃轉化溫度、熱分解溫度等性質的差異。此外，高分子也進行末端改質，和4-氯甲基苯乙烯反應，使高分子中含有雙鍵形成PPO-ST、PPO-BPA-ST、PPO-THP-ST，以利交聯反應的進行。由NMR計算，PPO-THP-ST擁有最高的雙鍵含量，且遠遠高於PPO-ST，因為PPO-THP-ST具備三個可改質基的緣故，這將使PPO-THP-ST在交聯反應後會有較好的熱性質，進而期待在產業中能有更好的應用。最後，聚苯醚主要應用於印刷電路板中，因此，我們也測試印刷電路板中最重要的參數介電常數(Dk)和耗散因子(Df)，並比較線性和非線性結構對此參數的影響。
並列摘要
In this thesis, eco-friendly synthesis methods of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) derivatives and synthesis of branched PPOs have been investigated. First, PPO was synthesized by oxidative polymerization of 2,6-dimethylphenol (DMP) in water using a water-soluble complex of copper and novel polymer ligands, poly(itaconic amide acid-co-acrylic acid)s. In the polymerization of DMP, the polymer ligands with various monomer ratios of itaconic amide acid:acrylic acid (4:6 and 2:8) were used, and effects of molecular weight and ratio of the polymer ligands on the polymerization of DMP were studied. The polymerization conditions were optimized varying precursor copper complexes, concentration of hydrogen chloride, molecular weight and monomer ratio of the polymer ligands, surfactant, and temperature, resulting in PPO with the best yield of 93% with number average molecular weight (Mn) of 3700 and molecular weight distribution (Mw/Mn) of 2.12. This yield is higher than that of previously reported conditions using arginine ligand in water (72%). Furthermore, the optimum condition was applied in copolymerization of DMP and 2-allyl-6-methylphenol (AMP) to provide their copolymer in 95% yield (Mn = 3000, Mw/Mn = 2.5). This allyl containing copolymer is expected to have thermally crosslinkable property; therefore its crosslinking reaction was carried out. On the other hand, recovery of the catalytic system of copper-polymer ligand was examined. The catalytic system maintains its activity even after recycling five times. Second, to obtain PPOs with higher number of crosslinkable groups, DMP was copolymerized with bifunctional bisphenol A (BPA) or trifunctional 1,1,1–tri(4-hydroxyphenol)ethane (THP) in the presence of copper complex to produce a linear poly(2,6-dimethyl-1,4-phenylene oxide-BPA) (PPO-BPA) and a branched polymer poly(2,6-dimethyl-1,4-phenylene oxide-THP) (PPO-THP) using methanol as solvent. Poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) was also synthesized by similar procedure for comparison. The obtained polymers were characterized by 1H NMR spectroscopy, viscosity measurement, dynamic light scattering analysis, differential scanning calorimetry, and thermogravimetric analysis. These polymers were used for termination reaction using 4-vinyl-benzyl chloride as a functionalized group in order to add double bonds at the polymer ends to form corresponding polymers (PPO-THP-ST, PPO-BPA-ST, and PPO-ST). The vinyl terminal groups are crosslinkable by thermal annealing. We estimated the vinyl-benzyl group ratio of the polymers by peak integral ratio of 1H NMR spectra. PPO-THP-ST contains higher vinyl-benzyl group ratio than that of linear polymers, resulting in higher reactivity in annealing reaction than the linear polymers. PPOs have often been used in application of printed circuit boards (PCBs). Therefore, we measured the dielectrical constant (Dk) and dissipation factor (Df) which are the most important factors in such application. Dk and Df values of the linear and branched polymers were compared.