本质阻燃PMMA/功能化石墨相氮化碳纳米复合材料的设计、制备及其性能改善机理研究

Aiming to reduce the fire hazards of PMMA resulting from the high flammability and releasing plenty of toxic smoke and gases during combustion, novel flame-retardant monomers containing nitrogen and phosphorus elements, and maleimide units are designed and synthesized. Moreover, metal oxide nanoparticles with catalytic decontamination property are loaded onto graphitic carbon nitride (g-C3N4) nanosheets to fabricate functionalized g-C3N4. Based on the combination of flame-retardant synergistic effect, nanocomposite technology and catalytic decontamination, both the flame-retardant monomers and the functionalized g-C3N4 are introduced into PMMA matrix to prepare a novel intrinsic flame-retarded PMMA/functionalized g-C3N4 nanocomposite. The nanocomposite obtained is expected to exhibit excellent flame retardancy, low toxicity and low smoke release. The influences of the flame-retardant monomers and the functionalized g-C3N4 on performances of the nanocomposites, such as flame retardancy, thermal properties, mechanical properties and transparency, are investigated; the internal relationship among the composition, structure and properties, and the reinforcement mechanism of the nanocomposites are also clarified. To explore the flame-retardant mechanism, products in gas phase and condensed phase of the nanocomposites obtained during pyrolysis or combustion are evaluated. The formation process of toxic products as well as the interaction between g-C3N4 nanosheets and metal oxide nanoparticles during the nanocomposite pyrolysis or combustion are studied to reveal the mechanisms of smoke suppression and catalytic decontamination. This project will not only provide the theoretical and experimental basis for the design and preparation of new PMMA nanocomposites with outstanding fire safety properties, but also open up a new way the desire of fire safety polymers.

本项目针对聚甲基丙烯酸甲脂（PMMA）存在易燃、且燃烧时释放大量有毒烟气等缺点，设计合成新型含磷、氮马来酰亚胺类阻燃单体和具备催化减毒性质的金属氧化物纳米颗粒功能化石墨相氮化碳（g-C3N4）。基于协同阻燃、纳米复合及催化减毒等原理，将二者结合应用于PMMA中，制备本质阻燃且低烟低毒的PMMA/功能化g-C3N4纳米复合材料。探讨阻燃单体和功能化g-C3N4的组成、结构对复合材料阻燃、热、力学、透明等性能的影响，构建材料组成-结构-性能关系，揭示复合材料性能改善机理；研究复合材料热解、燃烧时气相、凝聚相产物生成机制，揭示阻燃单体和功能化g-C3N4阻燃机理；研究复合材料热解、燃烧时有毒烟气的生成机理，探索g-C3N4和金属氧化物纳米颗粒的作用机制，揭示材料催化抑烟减毒机理；为新型火安全型PMMA纳米复合材料的设计与开发提供理论依据和实验基础，也为聚合物材料火安全性能设计开辟新的思路。

本项目针对聚甲基丙烯酸甲脂（PMMA）存在易燃、且燃烧时释放大量有毒烟气等缺点，设计合成新型含磷氮马来酰亚胺类阻燃单体（PMD），有机含磷改性二维结构的含镍化合物（M-Ni(OH)2），二维材料氧化石墨烯与石墨相氮化碳层层组装结构（g-C3N4/GO）及具有阻燃抑烟性质的二氧化铈纳米颗粒功能化石墨相氮化碳（CeO2@g-C3N4），然后分别将其引入到PMMA基体中成功制备PMMA纳米复合材料。基于协同阻燃、纳米复合及催化减毒等原理，制备本质阻燃且低烟低毒的PMMA/功能化g-C3N4等二维材料纳米复合材料。探讨阻燃单体和功能化g-C3N4等二维材料的组成、结构对复合材料阻燃、热、力学、透明等性能的影响，构建材料组成-结构-性能关系，揭示复合材料性能改善机理；研究复合材料热解、燃烧时气相、凝聚相产物生成机制，揭示阻燃单体和功能化g-C3N4等二维材料阻燃机理；研究复合材料热解、燃烧时有毒烟气的生成机理，探索g-C3N4等二维材料和金属氧化物纳米颗粒的作用机制，揭示材料催化抑烟减毒机理；为新型火安全型PMMA纳米复合材料的设计与开发提供理论依据和实验基础，也为聚合物材料火安全性能设计开辟新的思路。