纤维复合材料用含杂环结构新型环氧树脂的设计、合成及其结构与性能关系

It is well known that epoxy resins possessing excellent dimensional stability, high modulus, and creep properties, combined with the low melt viscosities of their precursors, are suitable for use as matrix resins in fiber-reinforced composites. However, their high crosslink density is typical brittle to give them poor damage tolerance, as well as the low heat resistance and hydrothermal property, which is restrictions in the use of epoxy resins. How to balance their heat resistance, hydrothermal property, and processibility during enhancing their fracture toughness is critical to broaden the application of epoxy in the field of aerospace. Herein, from the view of designing molecular structure, the phthalazinone moiety having wholly aromatic twisted noncoplanar structure will be introduced into the backbone of epoxy to gift the epoxy excellent thermal stability with good solubility. A series of difunctional, tetrafunctional and hyperbranch multifunctional epoxy will be designed and synthesized. Novel curing agents containing aromatic heterocyclic and ether structure will also be developed. The heat resistance, toughness and processability will be regulated by controlling the structure and crosslinking density of epoxy resin, and the structure and reactivity of the curing agents. Furthermore, a new toughening agent containing phthalazinone moiety, which have the different glass transition temperature segments, will be also explored. They have active pendent or end-capped groups which can be reacted with epoxy group. The interlaminar toughening will be adapted in order to benefit processing. We will investigate their synthetic technology and curing reaction. The resulting composites involving continuous fiber reinforced and fabric reinforced composites, will be researched. Their whole properties will be detected in details. The mechanism between the structure of the polymer molecular chain, processibility and character of service will be stated. These research in this project will be important academic significance and practical application value for developing new epoxy resin matrice which have excellent heat resistance, toughness and high strength.

针对航空领域纤维复合材料的环氧树脂存在耐热性、耐湿热性和抗冲击性能较差的问题，从环氧树脂基体、固化体系和增韧技术出发，全方位平衡其耐热性、耐湿热性、抗冲击性能与加工性能。从分子设计出发，将全芳香扭曲非共平面的二氮杂萘酮结构引入到环氧树脂分子骨架，设计、合成二官能度、四官能度和树枝化多官能度环氧树脂、新型含醚键和芳杂环结构的固化剂，通过调控环氧树脂的分子链结构和交联密度、固化剂的结构及反应活性来调控环氧固化物的耐热性、韧性以及加工性能；设计、合成含不同玻璃化转变温度链段的含二氮杂萘酮结构聚芳醚增韧剂，利用活性端基（或侧基）与环氧树脂进行反应，采用层间增韧方法，既改善韧性又利于成型。系统研究其合成技术、固化反应动力学和复合材料的服役性能，阐明“分子链结构-使用性能-加工性能”相互作用机制。本项目对研究耐高温、高强高韧的高性能环氧树脂体系的开发具有重要的学术理论意义和实际应用价值。

随着环氧树脂基复合材料在尖端技术领域需求增大，其耐热性低于200℃、质脆、耐高低温性能欠佳、不阻燃等性能缺陷越来越突出。本项目从分子设计出发，将全芳香扭曲非共平面的二氮杂萘酮结构引入到环氧树脂分子骨架，设计、合成了不同官能度含二氮杂萘酮结构环氧树脂，并改性商售环氧树脂，系统研究其合成技术、固化反应动力学及其复合材料的物理性能，阐述“分子链结构-使用性能-加工性能”相互作用机制。上述树脂体系均实现了耐高温、高强、高韧性、本征阻燃，且兼具良好的工艺性能。典型研究成果：.（1）研制成功四官能度含二氮杂萘酮结构环氧树脂（TEPZ），将其用于改性航空级AG-80。与纯AG-80相比，当TEPZ的添加量为AG-80的30wt%时，以4,4´-二氨基二苯砜为固化剂，共混树脂（AG80/30phrTEPZ/DDS）玻璃化转变温度高达281℃，提高了61℃，模量提高了27.8%（4.6 GPa Vs. 3.6 GPa），冲击性能提高46.2%（21.2K·Jm-2 Vs. 14.5·KJm-2），阻燃V-0级，在150℃下黏度为313mPa·S，凝胶时间82分钟。其T700碳纤维增强树脂基复合材料弯曲强度比纯AG-80复合材料的弯曲强度提高近20%（2038MPa Vs. 1700MPa），层间剪切强度提高了60%（92.4MPa Vs. 57.8MPa），说明引入二氮杂萘酮结构既提高了复合材料的力学强度，还改善了纤维和树脂的界面结合强度。.（2）研制成功缩水甘油醚类二氮杂萘酮环氧树脂ER30、生物基哒嗪酮环氧树脂、二官能度二氮萘酮结构环氧树脂，改性E44或者E51，均实现阻燃V-0，提高耐热性和模量，熔融加工流动性好，用含碳硼烷结构新型环氧树脂改性AG80/30phrTEPZ/DDS后，其热氧稳定性显著提高（空气800℃下，残炭率由0%提升到43%）。.（3）研制成功二氮杂萘酮聚芳醚砜酮（PPESK）增韧改性多官能团环氧树脂，挤出成型制备其碳纤维复合材料抽油杆，在深度大于3000m的油井推广应用，抽油系统效率平均提高12.2%，吨液耗电指标平均下降12.5kW.h/t。.本项目完全实现了研究目标。尤其AG80/30phrTEPZ体系（Tg=281℃）是目前报道耐热等级最高的环氧树脂，其耐热性高于传统双马来酰亚胺树脂，具有优异的加工性能和力学性能，拟将推广应用于航空航天等领域。