含取代侧基和芴结构可溶性聚酰亚胺的制备及其性能

PREPARATION AND PROPERTIES OF SOLUBLE POLYIMIDES CONTAINING SIDE SUBSTITUENT AND FLUORENE

利用自制含芴结构的二胺单体9,9-双[3,5-二甲氧基-4-(4-氨基-2-甲基苯氧基)苯基]芴和3种市售芳香二酐单体二苯醚四甲酸二酐、联苯四甲酸二酐、二苯酮四甲酸二酐,通过一步高温溶液缩合聚合法制备系列含取代侧基和芴结构的可溶性聚酰亚胺(PI,3a~3c)。利用核磁共振氢谱、凝胶渗透色谱、差示扫描量热等方法对该聚酰亚胺的结构、溶解性、耐热性和力学性能进行表征。结果表明:该系列聚酰亚胺能较好地溶于N,N-二甲基乙酰胺、N-甲基吡咯烷酮、二甲基甲酰胺、四氢呋喃等溶剂;其玻璃化转变温度高于244℃,在空气和N_(2)中的10%质量损失的温度分别高于460℃和500℃,耐热性优异;其薄膜的拉伸强度超过78.7 MPa,断裂伸长率超过7.9%,表现出较好的力学性能;该薄膜对CO_(2)和O_(2)的渗透系数分别高于15.9 barrer和4.95 barrer;对CO_(2)/CH_(4)和O_(2)/N_(2)的分离选择系数分别为46.42和4.93,具有良好的气体分离性能。

A series of soluble polyimides(3a-3c)containing side substituent and fluorene structures were prepared by one-step high-temperature solution condensation polymerization using self-made diamine monomer 9,9-bis(3,5-dimethoxy-4-(4-amino-2-methylphenoxy)phenyl)fluorene and three commercial available aromatic dianhydride monomers:diphenyl ether tetracarboxylic dianhydride,biphenyl tetracarboxylic dianhydride and benzophenone tetracarboxylic dianhydride.The structure,solubility,thermal stability and mechanical properties of the polyimide were characterized by 1H NMR,GPC,DSC and other equipment.The results showed that the polyimides could be well dissolved in N,N-dimethylacetamide,N-methylpyrrolidone,dimethylformamide,oxolane and other solvents.The glass transition temperature(T g)of the polyimide was higher than 244℃,and the 10%mass loss temperatures in air and N_(2) were higher than 460℃and 500℃,respectively,which proved that the thermal resistance of the polyimide was excellent.The tensile strength of the film was above 78.7 MPa,and the elongation at break was above 7.9%,which indicated good mechanical properties.The permeability coefficients of the film to CO_(2) and O_(2) were higher than 15.9 barrer and 4.95 barrer,respectively.The separation selectivity coefficients for CO_(2)/CH_(4) and O_(2)/N_(2) were as high as 46.42 and 4.93,which proved excellent gas separation performance.Therefore,this soluble polyimide with substituted side groups and fluorene structures exhibited excellent comprehensive performance.