Zhang Hao-Yang, Yuan Li-Li, Hong Wei-Jie, Yang Shi-Yong
Key Laboratory of Science and Technology on High-Tech Polymer Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China.
Polymers (Basel). 2022 Feb 28;14(5):965. doi: 10.3390/polym14050965.
With the goal of improving processability of imide oligomers and achieving of high temperature carbon fiber composite, a series of Thermosetting Matrix Resin solutions (TMR) were prepared by polycondensation of aromatic diamine (3,4'-oxybisbenzenamine, 3,4-ODA) and diester of biphenylene diacid (BPDE) using monoester of 4-phenylethynylphthalic acid (PEPE) as end-capping agent in ethyl alcohol as solvent to afford phenylethynyl-endcapped poly(amic ester) resins with calculated molecular weight (Calc'd M) of 1500-10,000. Meanwhile, a series of reactive diluent solutions (RDm) with Calc'd M of 600-2100 were also prepared derived from aromatic diamine (4,4'-oxybisbenzenamine, 4,4-ODA), diester of asymmetrical biphenylene diacid (α-BPDE) and monoester of 4-phenylethynylphthalic acid (PEPE) in ethyl alcohol. Then, the TMR solution was mixed with the RDm solution at different weight ratios to afford a series of A-staged thermosetting blend resin (TMR/RDm) solutions for carbon fiber composites. Experimental results demonstrated that the thermosetting blend resins exhibited improved melt processability and excellent thermal stability. After being thermally treated at 200 °C/1 h, the B-staged TMR/RDm showed very low melt viscosities and wider processing window. The minimum melt viscosities of ≤50 Pa·s was measured at ≤368 °C and the temperature scale at melt viscosities of ≤100 Pa·s were detected at 310-390 °C, respectively. The thermally cured neat resins at 380 °C/2 h showed a great combination of mechanical and thermal properties, including tensile strength of 84.0 MPa, elongation at breakage of 4.1%, and glass transition temperature (T) of 423 °C, successively. The carbon fiber reinforced polyimide composite processed by autoclave technique exhibited excellent mechanical properties both at room temperature and 370 °C. This study paved the way for the development of high-temperature resistant carbon fiber resin composites for use in complicated aeronautical structures.
为了提高酰亚胺低聚物的加工性能并制备高温碳纤维复合材料，以4-苯乙炔基邻苯二甲酸单酯（PEPE）为封端剂，在乙醇溶剂中，通过芳香二胺（3,4'-氧二苯胺，3,4-ODA）与联苯二酸二酯（BPDE）缩聚反应制备了一系列热固性基体树脂溶液（TMR），得到计算分子量（Calc'd M）为1500 - 10000的苯乙炔基封端聚（酰胺酯）树脂。同时，还以芳香二胺（4,4'-氧二苯胺，4,4-ODA）、不对称联苯二酸二酯（α-BPDE）和4-苯乙炔基邻苯二甲酸单酯（PEPE）在乙醇中反应制备了一系列计算分子量（Calc'd M）为600 - 2100的反应性稀释剂溶液（RDm）。然后，将TMR溶液与RDm溶液按不同重量比混合，得到一系列用于碳纤维复合材料的A阶段热固性共混树脂（TMR/RDm）溶液。实验结果表明，热固性共混树脂表现出改善的熔体加工性能和优异的热稳定性。在200℃/1h热处理后，B阶段的TMR/RDm显示出非常低的熔体粘度和更宽的加工窗口。在≤368℃下测得最低熔体粘度≤50Pa·s，在310 - 390℃分别检测到熔体粘度≤100Pa·s的温度范围。在380℃/2h热固化的纯树脂显示出机械性能和热性能的良好组合，依次包括拉伸强度84.0MPa、断裂伸长率4.1%和玻璃化转变温度（T）423℃。通过热压罐技术加工的碳纤维增强聚酰亚胺复合材料在室温及370℃下均表现出优异的机械性能。本研究为开发用于复杂航空结构的耐高温碳纤维树脂复合材料铺平了道路。
