热交联型共聚聚酰亚胺薄膜的制备及性能研究

Preparation and Properties of Thermal Crosslinking Copolymerized Polyimide Films

首先合成了一种含芴基、羟基以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(BAHOPF),再以BAHOPF和3,5-二氨基苯甲酸(DABA)为二胺单体、六氟二酐(6FDA)为二酐单体,通过缩聚反应和热亚胺化法制备了一系列聚酰亚胺(PI)薄膜。采用热重分析(TGA)、傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、核磁共振波谱(NMR)、紫外-可见光谱(UV-Vis)、差示扫描量热法(DSC)等测试手段表征了制备的二胺单体和PI薄膜的结构与性能。结果表明:制备的PI薄膜结晶度较低;随着芴基比例的增大,PI薄膜的透明度和力学性能有所提高;所有PI薄膜都表现出良好的热性能,其中5%热失重温度为309～464℃,10%热失重温度为400～510℃,玻璃化转变温度(Tg)约为350℃,且制备的PI薄膜具有较好的溶解性能。

Firstly, a 9,9′-Bis[4-(4-amino-2-hydroxybenzoxyl) phenyl] fluorene(BAHOPF) contianing fluorenyl, hydroxyl, and phenyl ether bond was synthesized. Then a series of polyimide(PI) films were prepared by condensation polymerization reaction and thermal imidization using BAHOPF and 3,5-diaminobenzoic acid(DABA) as diamine monomers, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6 FDA)as dianhydried monomer. The structure and properties of the prepared diamine monomer and PI films were characterized by thermogravimetric analysis(TGA), Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD), nuclear magnetic resonance spectroscopy(NMR), ultraviolet visible spectroscopy(UV-vis), and differential scanning calorimetry(DSC). The results show that the PI films exhibit low degree of crystallinity. With the increase of fluorenyl ratio, the transparency and mechanical properties of the PI films are improved. All PI films have good thermal properties and solubility, and their 5% thermal decomposition temperature is 309~464 ℃, 10% thermal decomposition temperature is 400~510 ℃,and the glass transition temperature(T_g) is about 350 ℃.