高温自增强特性的聚磷硅炔阻燃剂的设计合成及其改性环氧树脂研究

Epoxy resin has been widely used in aerospace, mechanical architecture and electronics because of its excellent chemical stability and processibility. The main factors to restrict its development are highly flammable and low mechanical property at high temperature. In this project, we focus on design and synthesis of poly(phosphorus-silicon-acetylene) flame retardant with phosphaphenanthrene group and SiC≡C structure in the side and main chain, respectively. The flame retardant and mechanical properties at high temperature of modified epoxy resin are improved by incorporation the flame retardant elements and self-crosslinking structure into the flame retardant structure. After that, the modified epoxy resin materials with the functions of heat resistance, flame retardant and self-reinforced are prepared. Furthermore, not only the side chain groups, molecular weight and the addition of poly(phosphorus-silicon-acetylene) flame retardant are adjusted and the content of the flame retardant elements and self-crosslinking structure in cured epoxy resin are changed, but also the temperature and degree of self-crosslinking reaction are controlled to analyze the mechanism of self-reinforced and flame retardant properties of the modified epoxy resin in detail, which will also help to reveal the internal relationship among structure-performance-mechanism. The modified epoxy resins are expected to be used as high temperature structure flame retardant materials in aerospace, electronics, power and other fields. All these researches above could provide a new strategy for the development of highly effective flame retardant and self-reinforced epoxy resin materials, which is also expected to be extended to other thermosetting resins and polymer systems.

环氧树脂因化学性质稳定和易于成型加工等特点而被广泛应用于航空航天、机械建筑和电子电气等领域，目前限制其发展的主要因素是易燃和高温力学性能偏低。本项目通过设计合成一类侧链含磷杂菲基团，主链为SiC≡C结构的聚磷硅炔阻燃剂，利用阻燃剂结构中的阻燃基元和高温自交联结构来提高改性环氧树脂的阻燃和高温力学性能，制备兼具耐热、阻燃和高温自增强作用的结构功能一体化改性环氧树脂材料。通过调整聚磷硅炔阻燃剂的侧链基团、分子量和添加量，改变环氧树脂固化物结构中阻燃基元和高温自交联结构的含量，控制自交联反应的温度和程度，解析聚磷硅炔改性环氧树脂的高温自增强和阻燃机理，揭示材料结构-性能-机理之间的内在联系，所制备的改性环氧树脂材料有望用作航空航天、电子电气和动力能源等领域的高温结构阻燃材料。本项目的研究将为发展高效阻燃和高温自增强作用的环氧树脂材料提供新思路，有望拓展到其他热固性树脂和聚合物体系。

本项目针对普通环氧树脂极易燃烧，阻燃改性后力学性能偏低的问题，设计合成多种DOPO基多功能高效阻燃剂，并用于提高环氧树指的阻燃、热稳定和力学性能。其中，所制备的DOPO基聚磷硅炔阻燃剂（PPESi）改性环氧树脂固化物具有优异的阻燃性能和抑烟效果，仅添加2.5 wt%即可通过UL-94的V-0等级，LOI值达到30.1%。EP/PPESi-5.0和EP/PPESi-10.0的THR分别为108 MJ/m2和103 MJ/m2，TSP分别为25 m2和23 m2，相比于EP/PPESi-0分别降低了30.8%和34.0%，24.0%和28.5%。同时，EP/PPESi-10.0的弯曲强度、冲击强度和拉伸强度分别为122.0 MPa、34.6 kJ/m2和87.6 MPa，分别提高了23.7%，41.8%和38.2%。此外，改性环氧树脂高温下的力学性能也得到提升，实现了环氧树脂阻燃和力学性能的同步提高。研究了改性环氧树脂的阻燃和力学性能等微观结构和宏观性能方面的规律，探索增强和阻燃机理，进一步拓宽了环氧树脂的应用范围。在项目执行过程中，相关成果共发表SCI论文6篇（均标注国家自然科学基金项目资助），授权发明专利4项。本项目的研究将为发展高效阻燃和优异力学性能的环氧树脂材料提供新思路，有望拓展到其他热固性树脂和聚合物体系。