Synthesis, characterization and properties of aromatic copolyimides containing Bi-benzimidazole moiety
Synthesis, characterization and properties of aromatic copolyimides containing Bi-benzimidazole moiety
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双苯并咪唑芳香族共聚酰亚胺的合成、表征及性能
DOI：
10.1007/s10965-015-0726-2
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发表时间：
2015-04-16
影响因子：
2.8
通讯作者：
Zhang, Qinghua
中科院分区：
文献类型：
--
作者：
Chen, Yingtao;Zhang, Qinghua
以3，3‘，4，4’-联苯四胺和对氨基苯甲酸为原料，在多聚磷酸中一步反应合成了新的芳香族杂环二胺单体2，2-双(4‘-氨基苯基)-5，5-双-1H-苯并咪唑(BAPBBI)。通过傅立叶变换红外光谱、核磁共振氢谱、核磁共振碳谱、质谱图和元素分析确证了化合物的结构。以均苯四甲酸二酐(PMDA)、4，4‘-氧基二苯胺(Oda)和不同摩尔比的BAPBBI为原料，制备了一系列含双苯并咪唑结构的共聚酰亚胺薄膜。通过在主链上引入BAPBBI，将聚苯并咪唑与聚酰亚胺结合在一起，得到了高度刚性的结构和增强的大分子相互作用，从而提高了材料的热稳定性和力学性能。例如，这些聚酰亚胺具有较高的玻璃化转变温度(408-438℃)和初始热分解温度(550-580℃)。它们具有123233兆帕的强拉伸强度和2.66-12.84 GPA的拉伸模数(不进行后拉伸)。450℃拉伸后的薄膜具有较高的力学性能，拉伸强度为195~554 Mpa，拉伸模数为4.6938.57 Gpa。
A new aromatic heterocyclic diamine monomer, 2, 2-bis (4'-aminophenyl)-5,5-bi-1H-benzimidazole (BAPBBI), was synthesized via a one-step reaction of 3,3', 4,4'-biphenyltetramine and p-aminobenzoic acid in polyphosphoric acids with the high yield and purity. FTIR, H-1 NMR, C-13 NMR, mass spectra and elemental analysis were employed to confirm the chemical structures. A series of copolyimide films containing the bi-benzimidazole moieties were prepared by the reaction of pyromellitic dianhydride (PMDA), 4,4'-oxydianiline (ODA) and BAPBBI with various molar ratios. The combination of polybenzimidazole and polyimide by introducing BAPBBI into the main chains brings the highly rigid structure and the enhanced macromolecular interactions, resulting in the enhancement in the thermal stability and the mechanical properties. For instance, these polyimides are endowed with a higher glass transition temperature of 408-438 degrees C and an initial thermal decomposition of 550-580 degrees C. They exhibit a strong tensile strength of 123233 MPa, and a tensile moduli of 2.66-12.84 GPa without post stretching. Meanwhile the stretched films at 450 degrees C exhibited the enhanced mechanical properties with the tensile strength of 195-554 MPa and the tensile modulus of 4.6938.57 GPa.