前端开环易位聚合合成本征阻燃PDCPD及其阻燃基元间的协效机理研究

Polydicyclopentadiene (PDCPD) is kind of a high-performance engineering plastics, but its relatively complex polymerization technology and flammability have greatly limited the application in many fields. Hence, in this project, the norbornene monomer (NB-M) containing flame retardant groups such as phosphorus/nitrogen, silicon and phenyl maleimide will be designed and synthesized, and then subsequent frontal ring-opening metathesis polymerization(FROMP) will be conducted with comonomer dicyclopendiene (DCPD) to prepare a series of intrinsic flame retardant PDCPD materials. The effects of NB-M’s structure and its norbornene group contents as well as its copolymerization feed ratio with DCPD on the aggregation structure of resultant PDCPD and the relationship with mechanical properties and flame retardancy will be investigated. Furthermore, the physical changes and chemical reactions of gas phase and condensate phase during combustion of intrinsic flame retardant PDCPD will be principally studied, and the effects of the gradual and multi-level introduction of flame retardant elements on the structure, composition and properties of pyrolysis products and carbon layers during combustion will also be investigated. Finally, the mechanism of synergistic flame retardancy of different flame retardant elements in PDCPD will be elucidated as well. Eventually, we intend to provide a deeper understanding of fundamental relationships between molecular structure of NB-M, FROMP technique, aggregate structure and flame retardancy and mechanical properties of resulting PDCPD materials. Therefore, this project provides a versatile and energy-efficient strategy for PDCPD materials with high flame retardance and tunable comprehensive physical and mechanical properties, showing both scientific significance and application prospects.

针对聚双环戊二烯(PDCPD)聚合反应过程难以控制和易燃等问题，本项目拟设计含阻燃基元的降冰片烯单体，通过它们与DCPD单体的前端开环易位共聚合反应(FROMP)，将磷氮、硅系和苯基马来酰亚胺阻燃基元引入PDCPD中，实现本征阻燃PDCPD的高效合成。研究降冰片烯单体结构和降冰片烯基元含量，共聚单体比例变化对PDCPD聚集态结构和机械、阻燃性能的影响，探讨其结构与性能之间的关系。重点研究本征阻燃PDCPD燃烧过程中，气相和凝聚相的物理转变和化学反应机理，探讨各阻燃基元逐步和多层次的引入，对PDCPD燃烧过程中裂解产物和炭层结构、组成和性能的影响，阐明阻燃基元间的协效阻燃机制，建立“阻燃共聚单体结构-FROMP工艺-聚集态结构-阻燃和机械性能”之间的构效关系，总结其规律，为高效合成本征阻燃的PDCPD树脂提供理论基础和技术途径。

本项目针对聚双环戊二烯(PDCPD)聚合反应过程难以控制和易燃等问题，设计合成了含阻燃基元的降冰片烯单体，通过它们与DCPD单体的前端开环易位共聚合反应(FROMP)，将磷氮、硅系和苯基马来酰亚胺阻燃基元引入PDCPD中，实现了本征阻燃PDCPD的高效合成。研究了降冰片烯单体结构和降冰片烯基元含量，共聚单体比例变化对PDCPD聚集态结构和机械、阻燃性能的影响，探讨其结构与性能之间的关系。重点研究了本征阻燃PDCPD燃烧过程中，气相和凝聚相的物理转变和化学反应机理，探讨了各阻燃基元逐步和多层次的引入，对PDCPD燃烧过程中裂解产物和炭层结构、组成和性能的影响，阐明了阻燃基元间的协效阻燃机制，建立“阻燃共聚单体结构-FROMP工艺-聚集态结构-阻燃和机械性能”之间的构效关系，总结了规律，为高效合成本征阻燃的PDCPD树脂提供了理论基础和技术途径。.在开展上述研究的同时，项目组通过借鉴本征阻燃策略，将其拓展到功能PDCPD复合材料的制备中，发现了一种高性能功能型PDCPD基复合材料的普适、高效、节能的制备方法，在高介电和电磁屏蔽PDCPD基复合材料的制备及应用等领域取得了一定的进展。并总结了PDCPD基复合材料内部填料-功能性单体-聚合物大分子链相互作用力层次、作用方式及过程的规律。并将该规律应用于可生物降解材料聚乳酸(PLA)的高性能化中，并在PLA的高性能化和功能化领域取得了一定成果，相关技术应用于北京冬奥会中。另外，项目组将上述热塑性和热固性聚合物结构调控及高性能化相关技术应用于智能工程装备用电线电缆材料的制造和严苛环境服役食品接触材料及保障装备的产业化中，并产生了明显的经济效益及社会效益。