一种含羟基的芴基Cardo型聚酰亚胺的合成及性能

Synthesis and Properties of Fluorenyl Cardo Polyimides Containing Hydroxyl

合成了一种含芴基、羟基及苯醚键的二胺单体9,9’-双[4-(4-氨基-2-羟基苯氧基)苯基]芴,将该二胺单体分别与六氟二酐(6FDA)、均苯四甲酸二酐(PMDA)、联苯四甲酸二酐(BPDA)、3,3’,4,4’-二苯酮四酸二酐(BTDA)和4,4'-联苯醚二酐(ODPA)聚合,通过热酰亚胺化法制备出了5种聚酰亚胺(PI)薄膜。采用热重分析、傅里叶变换红外光谱、X射线衍射、核磁共振、紫外-可见光谱、差示扫描量热分析和溶解性等测试手段表征了所制备的二胺单体和PI的结构与性能。结果表明,含羟基的芴基Cardo型聚酰亚胺为无定形结构,且大多数PI在N,N-二甲基甲酰胺(DMF)、N,N-二甲基乙酰胺(DMAc)、甲基吡咯烷酮(NMP)和二甲基亚砜(DMSO)等有机溶剂中具有良好的溶解性。而在热性能方面,PI-6FDA表现出最佳的热稳定性,其10%热分解温度为443℃。PI-6FDA、PI-PMDA和PI-BPDA的玻璃化转变温度分别为343℃、346℃和345℃。由于醚键使分子链的柔性提高,因此PI-ODPA展现出了最佳的力学性能。

A fluorenyl diamine monomer with hydroxyl and ether linkage 9,9’-bis[4-(4-amino-2-hydroxybenzoxyl) phenyl] fluorene was synthesized. Five kinds of polyimides (PI) were prepared from the diamine with 4,4'-(Hexafluoroisopropylidene)diphthalic anhydride (6FDA), pyromellitic dianhydride (PMDA),3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA),3,3',4,4'-benzophenonetetracarboxylic dianhydride(BTDA)and 4,4'-oxydiphthalic anhydride (ODPA) via the thermal imidization of poly( amic acid) respectively.The structure and properties of the diamine and PI were characterized by TGA, FT-IR, XRD, NMR, UV-vis, DSC, and solubility test. The results show that the fluorenyl Cardo polyimides containing hydroxyl exhibit amorphous structure. Most PI show good solubility in organic solvents such as DMF, DMAc, NMP and DMSO. PI-6FDA show the best thermal properties,10% thermal decomposition temperature is 443 ℃ and the glass transition temperature (Tg) of PI-6FDA, PI-PMDA and PI-BPDA is 343 ℃, 346 ℃ and 345 ℃ respectively.PI-ODPA has the best mechanical property because of ether linkage can improve the flexibility of molecular chains.