苯并恶唑
苯并噻唑
酰亚胺
乙醚
高分子化学
苯并咪唑
缩聚物
碳酸钾
二苯醚
苯
有机化学
玻璃化转变
单体
热稳定性
材料科学
化学
聚合物
标识
DOI:10.1177/0954008311421988
摘要
Three types of new bis(ether-amine) monomers such as 5-(2-benzimidazole)-1,3-bis(4-aminophenoxy)benzene (3), 5-(2-benzoxazole)-1,3-bis(4-aminophenoxy)benzene (4), and 5-(2-benzothiazole)-1,3-bis(4-aminophenoxy)benzene (5) were prepared in three steps, starting from the reaction of 3,5-dihydroxybenzioc acid with 4-fluronitrobenzene in N, N-dimethylformamide (DMF) solution in the presence of potassium carbonate, followed by catalytic reduction of the intermediate dinitro-carboxylic acids, and subsequent condensation of the resulting diamino-carboxylic acids and 1,2-phenylenediamine, 2-aminophenol or 2-aminothiophenol in polyphosphoric acid (PPA), respectively. Three series of modified poly(ether-imide)s (PEIs) bearing pendent benzimidazole, benzoxazole or benzothiazole groups were prepared from the bis(ether-amine)s with dianhydrides by a conventional two-stage process that included ring-opening polycondensation forming the poly(amic acid)s (PAA) and further thermal or chemical imidization forming poly(ether-imide)s. For comparative purposes, reference poly(ether-imide)s were also prepared by reacting bis(ether-amine) lacking pendent groups namely 1,3-bis(4-aminophenoxy)benzene (6) with the same dianhydrides under similar conditions. The modified polymers were obtained in quantitative yields with inherent viscosities between 0.52 and 0.83 dL g −1 . Experimental results indicated that all the PEIs had glass transition temperature between 221 and 283 °C, the decomposition temperature at 10% weight loss between 480 and 572 °C under nitrogen.
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