高强、高韧杂萘联苯聚芳醚热塑性树脂增韧苯并噁嗪树脂研究

The potential of polybenzoxazines has been recognized recently and some of them have found their application in the field of the high technology aerospace industry. These resins possess unique features, especially near-zero volumetric change upon curing and release of no by-product during curing. However, some approaches to overcome some of the shortcomings of polybenzoxazines have been proposed. Among them, the studies focus on modification of the inherent brittleness of the new developed thermosets. Toughening methodology includes preparation of polymer blends with rubbers, thermoplastic resins or rigid particles, and so on. The properties of the modified polybenzoxazines are expected to achieve suitable flexibility without descending thermal properties and humidity resistance. In this project, poly(phthalazinone ether)s having excellent thermal stability, outstanding mechanical properties are selected to toughen polybenzoxazines to provide the above potential properties hopely. First of all, from the view of designing molecules, the novel copoly(phthalazinone ether)s are designed and prepared keeping in mind that they have two kinds of segments: one segment has lower glass transition temperature (Tg) matched with the curing temperature of polybenzoxazines, hopely plastic deformation of the matrix during curing of polybenzoxazines, the other with high Tg and rigidity maintains high strength of the whole resulting polymer. Then the resulting copolymers will be endcapped by functional groups to improve the compatibility between the resulting copoly(phthalazinone ether)s and polybenzoxazines. Many works will be concentrated on screening the functional groups in order to react with polybenzoxazines. The effects of the structure of the segments, molecular weight, composition, functional group and their reactivity in the objective copoly(phthalazinone ether)s on curing reaction, microphase separation as well as mechanical properties of the blends will be intensively researched. The toughening mechanism of this system will be analyzed and then concluded from the above research facts. Finally, fiber reinforced the above-mentioned matrix composites will be studied. The comprehensive properties involving thermal properties, mechanical properties, especially impact properties like CAI values, will be detected in details. Their fracture mechanism will also be investigated. This project will offer the new resin matrix for aerospace industry. The relative research results obtained in this project will hope to help researcheres in exploring polybenzoxazines.

苯并噁嗪树脂具有固化时不释放小分子，固化收缩率小，体积接近零膨胀等突出的性能，在航空航天等领域有广阔的应用前景。但其存在脆性大、损伤容限低等缺陷。本项目拟采用耐高温、高强、高韧的热塑性杂环聚芳醚树脂增韧改性苯并噁嗪树脂，以期在增韧同时不降低其耐热性能和力学强度，并赋予优异的耐湿热性能。首先从分子结构设计出发，设计、合成含活性端基（或侧基）的杂环聚芳醚共聚物，使其一部分链段在固化过程中发生形变吸能，一部分链段具有高的Tg和高刚性。研究共聚物改性剂的链段化学组成结构、分子量、组成比例、反应性官能团的类型、反应活性等对共混树脂的固化反应特性、相分离过程、最终相结构、力学性能的影响和相互之间的关系，研究该体系的增韧机理，选择最优体系研究其树脂基复合材料的制备技术，研究复合材料的力学性能，尤其是冲击性能，探索复合材料的断裂机制。为航空领域提供新型高性能树脂，丰富热固性树脂增韧理论。

本项目针对苯并噁嗪树脂质脆、耐受冲击强度低等缺点对其增韧改性，实现了在不降低其力学强度和耐热性能的基础上提高其韧性。.（1）从分子结构设计出发，设计合成含联苯结构的杂萘联苯聚芳醚腈（PPBEN）树脂，其DMA结果表明，其中含联苯结构分子链段的玻璃化转变温度（Tg）在150~200℃，与苯并噁嗪树脂的固化温度相近，在固化过程中发生形变吸能，含二氮杂萘酮联苯结构分子链段的Tg在270~320℃，提供共聚物优异的耐热性能和高的力学强度。所得PPBEN/PBOZ共混体系的冲击强度比纯BOZ提高了237%，Tg提高了7℃左右，800℃氮气氛围下的残炭率提高了10%。PPBEN/BOZ/T700复合材料的层间剪切强度提高了30%左右，对其弯曲性能和耐热性影响不大。.（2）设计、合成了主链含有间苯、联苯和双苯基芴三种结构的超支化环氧树脂，系统研究超支化环氧树脂的骨架结构、分子量和添加量对共混体系性能的影响，研究结果表明，含双苯基芴结构的超支化环氧树脂对BOZ能够同时提高改性树脂的冲击强度、弯曲强度和储能模量。将杂萘联苯聚芳醚砜联苯共聚物（PPBES）、含双苯基芴结构的超支化环氧树脂（HBPEE）和PA-6粒子引入到CF/PBOZ复合材料。结果显示，CF/PBOZ/PPBES/HBPEE/PA复合材料较未改性复合材料的I型断裂韧性（GIC）提高了177%，弯曲强度提高了9%，弯曲模量提高了17%，ILSS提高了19%，且Tg不降低。HBPEE接枝的氧化石墨烯（GO-HE），添加量0.05wt%的GO-HE/PBOZ改性树脂的冲击韧性提高了139%，其T700碳纤维增强复合材料的GIC提高了160%，弯曲强度提高了26%，弯曲模量提高了19%，ILSS提高了16%。.（3）采用PBOZ和双马来酰亚胺树脂（BDM）共混改性，设计、合成固化剂烯丙基联苯二酚（DABP）。通过熔融共混方法制备共混体系BDM/DABP/PBOZ，研究不同配比的BDM：PBOZ对共混体系性能的影响。结果表明，当BDM与PBOZ树脂比例为1:1时，BDM/DABP/PBOZ共混体系固化后无缺口冲击强度提高了97%，弯曲强度和弯曲模量都有所提高，且呈现出韧性断裂的特征；共混树脂体系形成均相，其Tg介于BDM和PBOZ的Tg之间，比苯并噁嗪树脂提高了50℃，比双马来酰亚胺树脂略有降低，在800℃的残炭率却有所提高。