本质阻燃不饱和聚酯复合材料的制备、性能及阻燃机理研究

The unsaturated polyester composites have been widely used in the fields of transportation, electrical engineering and construction. However, the unsaturated polyester is highly flammable due to its molecular structure containing a large number of styrene crosslinked chains. The unsaturated polyester releasing a lot of heat and toxic smoke as it burning, has serious potential fire hazard and must be flame retardant treatment. Aiming at the potential fire hazard arisen from flammability of the unsaturated polyester composites, in this project, the flame retardant crosslinking monomer containing phosphorus, nitrogen and/or aromatic group which serve as the crosslinking and diluent agent are designed and synthesized, and the glass fiber are modified by organic flame retardants and/or inorganic nanounit. Then they are incorporated the unsaturated polyester to prepare high performance unsaturated polyester composites. The thermal stabilities, flame retardant and mechanical properties of the composites are systemically studied. The effect of the composition and chemical structure of the synthesized flame retardant and the flame retardant nanolayers grafted or built on the surface of the modified glass fiber on the preparation processes and properties of the composites is revealed. The variation of the composition and structure of the gas and condensed phase products in the process of pyrolysis and combustion of composites are studied to explore the flame retardant mechanism. The variation of heat and toxic smoke release are investigated to develop the evaluation method of fire safety of the composites, and to reveal the intrinsic relationship of the structures and properties. The achievement of this project will bring out the design optimization of the fire safety of the high performance unsaturated polyester composites and build up the theoretical and experimental basis for the expansion of its application fields.

不饱和聚酯复合材料广泛应用于交通运输、电气和建筑等领域。但是由于不饱和聚酯分子结构中含有大量苯乙烯交联链段，遇火极易燃烧，同时释放出大量热量和有毒有害烟气，火灾危害性严重，必须进行阻燃处理。本项目针对不饱和聚酯复合材料的潜在火灾危险性，设计合成含磷、氮等阻燃元素的乙烯基阻燃交联单体，作为阻燃剂的同时，取代苯乙烯作为稀释交联剂，进一步结合玻璃纤维的纳米阻燃表面改性，制备热稳定性、阻燃和力学性能优良的不饱和聚酯复合材料。研究阻燃交联单体及改性玻纤表面的纳米阻燃改性层的组成与结构对材料的制备、成型工艺以及热稳定性、力学和阻燃性能等的影响；研究材料热解和燃烧过程中气相和凝聚相组成与结构的变化规律，研究其中的微观反应机制，揭示阻燃机理；研究材料燃烧的热量和毒害烟气的生成与释放规律，发展其火灾危险性分析方法。本项目的研究将为不饱和聚酯复合材料提出火安全优化设计方案，为拓展其应用领域奠定理论和实验基础。

不饱和聚酯树脂（UPR）被广泛应用于国民经济和国防军工等各个领域。但是UPR本质易燃，燃烧时释放出大量热量和有毒烟气，存在严重的火灾安全隐患。本课题针对UPR易燃、烟气毒性大等问题，发展高效阻燃、抑烟和减毒新方法：（1）合成含磷阻燃型稀释交联剂（含双键端基的有机磷化合物和含磷丙烯酸酯类化合物）；（2）合成含磷氮阻燃不饱和聚酯线型低聚物；（3）通过将超支化含磷氮有机阻燃剂接枝到无机纳米结构（氮化硼、石墨烯、二氧化硅纳米球）的表面，制备出阻燃型有机-无机杂化纳米结构；通过将催化性金属氧化物或化合物负载在氧化石墨烯或碳纳米管表面，制备出抑烟减毒型无机-无机杂化纳米结构；（4）通过采用反应性含磷阻燃剂接枝改性增强纤维或者采用阻燃性有机电解质或纳米结构通过层层组装改性增强纤维，制备出阻燃增强纤维。将阻燃型稀释交联剂、阻燃UPR线型低聚物、杂化纳米结构、阻燃增强纤维分别与传统UPR线型低聚物复合，制备性能优良的阻燃UPR复合材料。系统研究不同组分对材料性能的影响，结果表明阻燃材料的热稳定性、阻燃性能和力学性能显著提高，具有优良的火灾安全性；（5）开展阻燃UPR复合材料的燃烧及烟气生成特性实验研究，并结合热重-红外光谱-质谱联用、拉曼光谱等技术，研究阻燃材料热解和燃烧过程中气相和凝聚相产物的演化规律，发现UPR热解的气相产物中易燃的碳氢化合物和一氧化碳以及生烟的芳香族化合物的释放量均显著减少，同时产生了大量能够终止燃烧反应的气态含磷氧化物，并且燃烧后残余炭渣的致密度和石墨化程度均显著提高。推导出阻燃、抑烟和减毒机理：阻燃型交联剂和阻燃不饱和聚酯线型低聚物兼具凝聚相催化交联成炭和气相捕捉自由基的多重作用机理；杂化纳米结构是包括凝聚相中物理阻隔吸附、催化成炭和气相中自由基俘获、可燃气体稀释等作用的协同作用机理；而阻燃增强纤维主要是凝聚相成炭机理。本课题的研究为不饱和聚酯复合材料的火灾安全设计提供了坚实的实验基础和理论指导。