基于DOPS/磷腈结构的氮磷硫协同阻燃剂的分子设计与阻燃机理研究

In recent years, phosphaphenanthrene and its derivatives have been widely used in flame retardant epoxy resin(EP) because of their high reactivity and good compatibility in EP. However, its flame retardant efficiency is not high, the formation promotion of residue char of EP is not remarkable, and the enhancement of flame retardant effect is limited. One of the effective ways to solve these problems is combined between phosphaphenanthrene and phosphazene with their synergistic effect to build a new type of high efficiency flame retardant system. This project aims to prepare several novel synergistic flame retardants based on molecular design method and apply them to the flame retardant EP. First, the effects of bridge bond variety on synergistic flame retardant behavior are conducted to reveal the influence rules of different bridge bonds on the material degradation route and synergistic flame retardant mechanism; secondly, the effects of group ratio change on synergistic flame retardant behaviour are executed to clarify the dose-response relationship of the compound based on DOPS and phosphazene groups in EP; Finally, the effects of different introducing methods on synergistic flame retardant behavior are studied to elaborate the synergistic mechanism of DOPS and phosphazene double functional groups. This project is expected to expand the application range of DOPS/phosphazene double functional groups compound in the field of flame retardancy, so as to provide references for the design and synthesis of novel high efficiency double functional groups compound flame retardants in the future.

近年来，磷杂菲类阻燃剂因反应活性高、相容性好而被广泛应用于阻燃环氧树脂（EP）。然而，它具有阻燃效率不高、对EP的残炭生成促进作用不显著、对阻燃效果的提升有限等缺点。而解决这些问题的有效途径是将9,10-二氢-9-氧杂-10-磷杂菲-10-硫化物 (DOPS) 和磷腈进行复合，发挥二者的协同效应，构建新型高效阻燃体系。本项目拟采用分子设计的方法，制备几种新型结构的协同阻燃剂，并将其用于阻燃EP。首先，研究分子内桥键变化对材料协同阻燃行为的影响，揭示不同桥键对材料降解路线及协同阻燃机理的影响规律；其次，研究分子内基团比例变化对材料协同阻燃行为的影响，阐明DOPS/磷腈双基化合物在EP中的量效关系；最后，研究不同引入方式对材料协同阻燃行为的影响，明确DOPS和磷腈双基协效的作用机理。本项目将有望扩展DOPS/磷腈双基化合物在阻燃领域的应用范围，为今后设计合成新型高效双基化合物阻燃剂提供借鉴。

在环氧树脂的有机磷阻燃研究过程中，磷杂菲类阻燃剂由于具有反应活性高、相容性好等优点而被广泛深入研究。但是它阻燃效率不高、对EP的残炭生成促进作用不显著、对阻燃效果的提升有限。而解决这些问题的有效途径就是利用DOPS和磷腈基团之间的协同阻燃效应，构建新型高效阻燃体系。本项目主要包括以下研究内容：（1）通过分子设计合成了6种含有DOPS/磷腈结构的新型阻燃剂，获得了多种具有优异阻燃性能的环氧树脂复合材料，研究了其阻燃行为规律和机理，结果表明：DOPS和磷腈基团之间存在协同阻燃效应。（2）通过调整同一阻燃剂分子和同一复配体系中DOPS和磷腈基团的比例，制备了含有不同DOPS和磷腈基团比例的氮磷硫协同阻燃剂和不同复配比例的复合阻燃剂DOPS/HPCTP，利用协同阻燃效应获得了阻燃性能优异的EP复合材料。研究了DOPS与磷腈的基团比例变化对材料的阻燃性能和热降解行为的影响规律，探究了协同阻燃规律和协同阻燃作用机理。研究表明，DOPS和磷腈基团分别在气相和凝聚相发挥协同阻燃作用，通过优化二者的比例，有利于气相和凝聚相组分最大限度地发挥其协同阻燃作用。（3）研究了两种不同引入方式对材料的阻燃性能、热性能和力学性能以及协同阻燃行为的影响。结果表明：添加型和反应型阻燃剂均能改善EP的阻燃性能，在相同添加量下，反应型阻燃剂阻燃EP的阻燃性能和力学性能均好于添加型。（4）扩展研究了MAH-DOPS，DOPS-HQ和DOPS-PHBA等其它磷硫协同阻燃剂，并将其分别应用于环氧树脂和聚乳酸中，均表现出了明显的协同阻燃效应。本项目研究为双基协效和多元素协同阻燃剂的分子设计提供了借鉴，为环氧树脂的阻燃改性开辟了新的途径。