含吡啶环结构的共聚聚酰亚胺薄膜的制备及性能研究

Preparation and properties of copolyimide films containing pyridine ring structures

首先,合成了一种同时含有吡啶环结构和叔丁基的“Y型”二胺单体4-(4′-叔丁基)苯基-2,6-二(4′-氨基苯基)吡啶(TPAPP),然后与2,2-双(3-氨基-4-羟基苯基)六氟丙烷(6FAP)和4,4′-(4,4′-异丙基二苯氧基)双(邻苯二甲酸酐)(BPADA)聚合,经热酰亚胺化制备出一系列共聚聚酰亚胺(PI)薄膜。通过红外光谱、X-射线衍射、紫外-可见光谱、拉伸测试、动态热机械分析、热重分析和溶解性测试,对PI薄膜的结构和光学性能、力学性能、热性能及溶解性进行研究。结果表明:随着TPAPP摩尔分数的增加,共聚聚酰亚胺薄膜的光学透明性和玻璃化转变温度均表现出增加趋势。当二胺与二酐的物质的量之比为5∶5时,共聚聚酰亚胺薄膜的力学性能最好,拉伸强度达到144.9 MPa,杨氏模量为3.4 GPa,断裂伸长率可达9.3%。此外,这些共聚聚酰亚胺在非质子极性溶剂中均表现出较好的溶解性。

Firstly,a Y-shape diamine monomer 4-(4′-tertbutyl)phenyl-2,6-di(4′-aminophenyl)pyridine(TPAPP)containing pyridine ring structure and tertbutyl group was synthesized.Then,it was polymerized with 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane(6FAP)and 4,4′-(4,4′-isopropyldiphenyloxy)bis(phthalic anhydride)(BPADA),and a series of copolyimide(PI)films were prepared by thermal imidization.The structure and optical,mechanical,and thermal properties as well as solubility of the PI films were investigated by infrared spectroscopy,X-ray diffraction,UV visible spectra,tensile tests,dynamic thermo-mechanical analysis,thermogravimetric analysis,and solubility tests.The results show that as the molar ratio of TPAPP increases,the optical transparency and glass transition temperature of the copolyimide films exhibit an increasing trend.When the molar ratio of diamine and dianhydride is 5:5,the copolyimide film shows the best mechanical properties,with the tensile strength of 144.9 MPa,the Young's modulus of 3.4 GPa,and the elongation at break of 9.3%.In addition,these copolyimides demonstrate good solubility in aprotic polar solvents.