低温酰亚胺化法制备共聚型聚酰亚胺材料

Preparation of Copolymerized Polyimide by Low-Temperature Imidization

以4,4′-二氨基二苯醚(ODA)、均苯四甲酸二酐(PMDA)、3,3′,4,4′-二苯甲酮四酸二酐(BTDA)、3,3′,4,4′-联苯四酸二酐(BPDA)制备共聚型聚酰亚胺(PI)的前驱体聚酰胺酸(PAA),分别加入对羟基苯甲酸(PHA)、喹啉(QL)、苯并咪唑(BI)、苯丙三氮唑(BTA)、三乙胺(Et3N)、1,8-二氮杂二环[5.4.0]十一碳-7-烯(DBU),促使PAA在低温下酰亚胺化。利用傅里叶变换红外光谱仪、电子万能试验机、差示扫描量热仪、热重分析仪等研究了不同固化催化剂的催化活性及其对PI薄膜性能的影响。结果表明:固化催化剂能够降低PAA的酰亚胺化温度,其中BI,PHA和QL可使PAA的酰亚胺化过程在不高于180℃下完成,而PI/QL薄膜的拉伸强度及弹性模量分别为154.20 MPa、2430 MPa,能同时较好地保持PI薄膜的力学性能与热稳定性能。

4,4′-Oxydianiline(ODA),Benzenetetracarboxylic anhydride(PMDA),3,3′,4,4′-benzophenonetetracarboxylic dianhydride(BTDA),and 3,3′,4,4′-Biphenyltetracarboxylic dianhydride(BPDA)were selected to prepare precursor polyamic acid(PAA)of copolymerized polyimide(PI).P-hydroxybenzoic acid(PHA),quinoline(QL),benzimidazole(BI),benzotriazole(BTA),triethylamine(Et_3N)and 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU)were used to promote its imidization at lower temperature.Fourier transform infrared spectroscopy,electronic universal testing machine,differential scanning calorimeter and thermogravimetric analysis were used to study the catalytic activities of different curing catalysts and their effects on the properties of PI films.The results show that curing catalysts can reduce the amidation temperature of PAA.Among them,BI,PHA and QL can complete the imidization process of PAA at no more than 180℃,and the tensile strength and elastic modulus of PI/QL film are 154.20 MPa and 2430 MPa respectively,which can better maintain the mechanical properties and thermal stabilities of PI films at the same time.