中文摘要：

通过氟烷基化及结构设计可获得具有良好热稳定性、介电常数和介电损耗较低的新颖结构的聚酰亚胺，可望有效用于高透波涂层体系．在Pb／C催化下，4．硝基氯苯与2-氟4一硝基苯酚反应合成硝基化合物2-氟．4-硝基-1-（4-硝基苯氧基）苯（FNNB），其与水合肼反应生成二胺单体4-（4-氨基苯氧基）-3-氟苯胺（APFA），进而与芳香对称二酐单体6FDA反应合成芳香不对称聚酰亚胺．通过红外光谱和热重一差热跟踪检测确定聚酰胺酸及其亚胺化过程；通过红外光谱、氢核磁共振谱、差示扫描量热分析等表征确定聚酰亚胺的特定结构；对聚酰亚胺流延膜采用热重一差热分析、原子力显微镜观测、紫外一可见分光光度以及介电常数（8）、介电损耗（tan6）等检测．结果表明：膜表面颗粒尺寸均匀，平均粗糙度为9．024nm；在可见光区透过率〉80％；分解温度均超过500℃；1MHz和10MHz时，经250℃固化膜的s分别为3．65和2．38，tan6峰值为0．0107．

英文摘要：

Novel polyimide with better thermostability, lower dielectric constant and constant loss synthesized by fluorinated modification and molecular structural design and predicted as coatings with were highly electromagnetic wave permeability. 4-（4-aminophenoxy）-3-fluoroaniline （APFA） was obtained by 2-fluoro-4- nitrophenol and 4-nitrochlorobenzene, then the formed 2-fluoro-4-nitro-1-（ 4-nitrophenoxy ） benzene （ FNNB ） was transferred by catalytic reduction with hydrazine hydrate and catalyst of Pd/C. The asymmetric fluorinated was synthesized with 6FDA in DMAc solution by imidization of polyamie acid. Asymmetric polyimide exhibited excellent thermal stability with the decomposition temperature and the glass transition temperature of 502. 50 and 251.60 ~C. The residual weight （Rw） at 700 ~C was 49. 86%. AFM images of polyimide film showed that the grain sizes were in narrow ranges with evenly surface and mean roughness of 9. 024 nm. The UV-Vis absorption edge was at 357 nm and the transparency at 450 nm was higher than 80%. The dielectric constant was 3.65 at 1 MHz and 2. 38 at 10 MHz, and the maximum dielectric loss was 0. 010 7.