金属杂化POSS协同磷氮构筑新型阻燃环氧树脂

In this project, based on the structure of the cage-like Polyhedral Oligomeric Silsesquioxane (POSS) and functional design, two types of flame-retardant system are designed by introducing metal elements to POSS which are further combined with phosphorus/nitrogen elements as follows: metal hybrid POSS-P/N flame-retardant molecule and reactive metal hybrid POSS-P/N polymeric flame-retardant. By using the obtained metal hybrid POSS-P/N in flame-retardant epoxy resin, the factors and mechanism of flame-retardant are thoroughly investigated. The features of this project include: (1) the metal doping of POSS has advantages of high selectivity of catalytic effect on the decomposition of polymer chain, the promotion of carbonization of polymer, reduction of heat release and effective improvement of carbonization of nanoparticles region and flame-retardant of resin; (2) controllable construction of the flame-retardant composite material by self-assembly techniques will improve the compatibility of metal hybrid POSS-P/N flame-retardant and the polymeric substrate, and confine the flame-retardant elements in nanoscale region. This project will not only avoid the weakening of the physical and chemical properties of the matrix caused by flame-retardant, but also improve the advantage of nanocomposite flame-retardant and multi-element-based flame-retardant. Therefore, the prepared polymer is expected to enhance the flame-retardant performance, reduce the amount of retardant needed and improve the thermal and mechanical properties of the resin matrix.

本项目拟从笼形低聚倍半硅氧烷（POSS）单元结构和功能设计出发，引入金属元素到POSS中，结合磷/氮阻燃元素构筑两类阻燃体系：金属杂化POSS-P/N阻燃剂小分子和反应型金属杂化POSS-P/N聚合物阻燃剂，再将制备的金属杂化POSS-P/N应用于阻燃环氧树脂，全面探讨阻燃性能影响因素，深入研究阻燃机理。本项目特色在于：（1）独特的杂化金属的存在，对高分子链的裂解路径具有催化选择作用，可以促进聚合物成炭，降低热释放，有效改善纳米粒子间区域的成炭性和树脂的阻燃性；（2）通过自组装技术，实现多基元纳米阻燃复合材料的可控构筑，增强金属杂化POSS-P/N阻燃剂与聚合物基材的相容性，实现将阻燃元素限制在纳米尺度。本项目研究既可避免阻燃剂对基体其它物理化学性能的弱化，又能同时发挥纳米复合阻燃和多元素协同阻燃的优势。因而，有望在更低的添加量下全面提升聚合物阻燃性能指标，并提升基体的热、机械性能。

本项目完成金属杂化笼形POSS协同磷氮构筑新型阻燃环氧树脂的研究。首先合成出金属杂化POSS-P/N分子以及复配型复合物，构筑金属/有机/无机多元协同无卤纳米阻燃体系，制备出环氧树脂纳米复合材料，获得阻燃性能、热性能和机械性能。其次，合成出以三嗪结构为中心且P/N比例可调的分子，获得阻燃元素的最佳比及其对阻燃剂反应性的控制，由此设计出同时含POSS、磷杂菲和三嗪基元的分子内杂化物，可在环氧中自组装，实现低添加量下阻燃增强增韧多重效果。最后分析影响因素并掌握金属杂化POSS协同磷氮阻燃体系的阻燃机理。本工作为无卤低毒绿色阻燃体系及阻燃环氧树脂复合材料的设计提供了基础依据，研究具有积极意义。.㈠金属杂化POSS-P/N分子及复配型复合物制备：①基于“顶角开笼+缩合”和“顶角盖帽法+取代”两条路线合成出金属杂化POSS分子，进而通过Kabachnik-Fields反应，制得Ti/Zr杂化POSS-P/N分子。②基于金属配位作用和Kabachnik-Fields反应，合成出Fe/Cu杂化POSS-P-N络合物。③基于金属有机试剂和磷杂菲衍生物复配制得金属杂化阻燃体系。④基于可逆加成-断裂链转移RAFT聚合方法和侧链接枝反应，得到POSS基含磷/钛的共聚物。.㈡阻燃元素P/N比例的可控调节及其对环氧树脂透明性、热性能、阻燃性能以及力学性能的影响规律。发现提高磷氮比可提升阻燃剂与环氧树脂相容性并影响阻燃剂反应活性。.㈢金属杂化POSS-P/N协同阻燃改性环氧树脂的制备、性能及阻燃机理研究。与磷杂菲化合物DOPO相比，添加金属元素的POSS-P/N杂化分子和复配物阻燃体系发挥了金属、硅、磷/氮多元素的协同作用。金属对高分子链的裂解路径具有催化选择作用，更好促进聚合物成炭。改性环氧树脂具有更高的极限氧指数、残炭量以及更低的热释放和烟释放，垂直燃烧UL-94等级达V-0级别。.㈣发现燃烧过程中有机钛转变成热力学稳定相的金红石结构，促进了残炭生成，极大提高了阻燃性。.㈤发表13篇中英文学术期刊论文，其中SCI收录9篇，EI收录2篇，中文核心2篇。获得国家发明专利授权12件。