均相磷杂化纳米SiO2与原位生成的聚氨酯弹性体增韧阻燃环氧树脂研究

Epoxy has widely demand in the fields of aeronautics and astronautics industry, electrical and electronic appliances, construction and transportation, etc. However, its poor toughness and easily burning characteristic terribly limit its application. On consideration of the shortcomings of current research, a dual toughened route fabricated by homogeneous phosphorus hybrid nano-silica with high phosphorus content and in-situ formed polyurethane elastomer was proposed, so as to improving the toughness and flame retardancy of epoxy simultaneously. This study will focus on the preparation and characterization of homogeneous phosphorus hybrid nano-silica with high phosphorus content, the preparation, interfacial characteristic, mechanical properties and flame retardation of the epoxy composites. Besides, the scientific issues as follow: the toughen mechanism of nano-silica and polyurethane elastomer, the relationship between the structure and mechanical properties of the composite, the flame retarded mechanism of phosphorus hybrid nano-silica, and the relationship between the structure, the flame retarded performances and the flame retarded mechanism of phosphorus hybrid nano-silica would also be clarified, which may provide theoretical support for the development of high performance epoxy composites.

环氧树脂在航空航天、电子电气、建筑交通等领域有非常广泛的需求。本项目针对其韧性差、易燃烧严重限制其应用的缺点，分析现有研究的不足，提出“双重增韧法”，设计制备高磷含量的均相磷杂化纳米SiO2，并在此基础上制备环氧树脂/原位生成的聚氨酯弹性体/均相磷杂化纳米SiO2复合材料，以实现增韧环氧树脂并提高其阻燃性能的目的。本项目中，我们将就高磷含量均相磷杂化纳米二氧化硅制备、结构表征、环氧树脂复合材料制备、复合材料界面特性、复合材料力学性能和阻燃性能等开展研究，并阐明磷杂化纳米SiO2与原位生成的聚氨酯弹性体在环氧树脂中的增韧机理、复合材料结构与力学性能之间的关系、磷杂化纳米二氧化硅的阻燃机理、阻燃剂结构-阻燃性能-阻燃机理之间的关系等科学问题，为高性能环氧树脂复合材料的研发提供理论支持。

环氧树脂在航空航天、电子电气、建筑交通等领域有非常广泛的需求。本项目针对其韧性差、易燃烧严重限制其应用的缺点，开展了相关的研究工作，主要研究内容包括：（1）分别基于苯基磷酰二氯和哌嗪，植酸和正硅酸乙酯，DOPO和γ氨丙基三乙氧基硅烷，合成了用于阻燃环氧树脂的含磷成炭剂BPOPA，植酸型磷杂化二氧化硅PA@SiO2、DOPO型磷杂化二氧化硅DOPO@SiO2；（2）研究了BPOPA、PA@SiO2和DOPO@SiO2在环氧树脂中的阻燃效果，三种阻燃剂在环氧树脂中均具有好的阻燃效果，DOPO@SiO2单独使用（15wt%）即可使环氧树脂获得好的阻燃性能，垂直燃烧达到V-0级，而BPOPA和PA@SiO2需要和APP复配使用；（3）研究了BPOPA、PA@SiO2和DOPO@SiO2的阻燃机理，BPOPA和PA@SiO2主要在凝聚相发挥阻燃效果，DOPO@SiO2主要在气相发挥阻燃效果，同时DOPO@SiO2中的P元素在固相中也参与了成炭；（4）通过聚乙二醇和4,4’-亚甲基二苯基二异氰酸酯反应，在环氧树脂材料基体中引入了原位生成的聚氨酯弹性体，DOPO@SiO2和原位生成的聚氨酯弹性体对环氧树脂具有好的增韧效果，含DOPO@SiO2和原位生成的TPU的EP材料脆断面呈现典型的韧性断裂特征，EP/15DOPO@SiO2/30TPU与纯EP相比，冲击强度约提升89.0%。本项目的研究思路和研究成果推动了阻燃增韧型环氧复合材料的发展，为继续开展环氧树脂的增韧和阻燃研究提供了一定的参考。