磷腈/三嗪双基分子阻燃聚乳酸树脂的性能与机理

For constructing high-efficiency flame retardant molecules based on phosphazene and triazine groups in polylactide, and obtaining the design rule of the molecular structures and their flame retardant mechanism, a novel phosphazene-triazene double-group molecule and their derivatives with different terminal groups will be prepare by using cyanuric chloride and hexachlorocyclotriphosphazene in the project. The effect of phosphazene-triazene double-group molecules on thermal properties and flame retardancy of polylactide will be studied and their double-group flame retardant synergistic effect will be dissected. The effect of terminal group on the properties of polylactide will be studied by comparing the properties of polylactide containing phosphazene-triazene double-group molecules with different terminal groups. In order to improve the flame retardant efficiency, composites of phosphazene-rich or triazene-rich compound and phosphazene-triazene double-group molecules will be added in polylactide to optimize the ratio of phosphazene to triazene groups. The flame retardant property of this polylactide will be researched. Nano-metal compound will be introduced into the phosphazene-triazene double-group molecule by in situ doping method and their flame retardant polylactide composites will be prepared. The mechanism of synergistic flame retardant between Nano-metal compound and phosphazene-triazene double-group molecules will be explored. The project will bring new members into the non-halogen flame retardant polylactide area, extend the research of flame retardant mechanism into new areas, and carry out the new scientific practice in constructing novel phosphazene-triazene double-group high-efficiency flame retardant molecules.

为构建在聚乳酸中具有高效阻燃作用的磷腈/三嗪双基分子，获得该类分子的结构构建规律及阻燃机理，本申请以三聚氯氰和六氯环三磷腈为主要原料制备了一种新型结构的磷腈/三嗪双基分子并对其端基进行功能化修饰，研究磷腈/三嗪双基分子对聚乳酸树脂阻燃性能和热性能的影响规律，剖析磷腈/三嗪基团的双基阻燃协同效应，通过对比端基结构不同的双基分子阻燃聚乳酸的性能，获得端基结构对阻燃聚乳酸性能的影响规律；为提高双基分子的阻燃效率，通过复配含磷腈或三嗪基团的阻燃剂进一步优化双基分子中三嗪与磷腈基团的比例，研究复配体系阻燃聚乳酸的阻燃效果，通过原位掺杂的方式将纳米金属化合物引入到双基分子中，研究双基分子原位掺杂纳米金属化合物阻燃聚乳酸的性能表现，剖析在复配和掺杂条件下磷腈与三嗪基团提效作用模式和机理。本申请将为无卤阻燃聚乳酸增添新的选择，为提效阻燃机理研究扩展新的方向，为构建新型高效阻燃的双基分子进行新的科学实践。

本项目共设计并合成了四种磷腈/三嗪双基分子（A1、A2、A3、A4）和一种磷腈/三嗪双基分子原位掺杂纳米氧化锌的化合物（A4-d-ZnO），并将其用于阻燃聚乳酸树脂。具体包括以下四部分内容：（1）合成了一种磷腈和三嗪基团比例固定的双基分子HTTCP（A1）并将其用于阻燃聚乳酸树脂，研究了其在聚乳酸树脂中的基团协同阻燃效应及作用机理。实验结果证明，磷腈/三嗪双基分子通过发挥气相和凝聚相双相协同阻燃机理达到高效阻燃的效果。（2）在HTTCP的基础上通过改变端基种类合成了3种具有不同端基结构的磷腈/三嗪双基分子，研究了端基结构对阻燃聚乳酸的性能影响规律。阐明了端基结构影响磷腈/三嗪双基分子阻燃聚乳酸体系阻燃性能的作用机理。实验结果表明，端基为烷胺基的磷腈/三嗪双基分子能够发挥最好的阻燃效果，可归因于凝聚相的成炭作用、炭层的屏蔽保护作用、气相中PO2·的自由基淬灭作用和H2O, CO2, NH3等的稀释可燃气体作用。（3）将磷腈/三嗪双基分子HTTCP与含磷腈基团的化合物六苯氧基环三磷腈（HPCTP）复配阻燃聚乳酸，通过外部添加磷腈基团来调控阻燃体系中磷腈基团和三嗪基团的比例，研究其对阻燃聚乳酸性能的影响规律及提效阻燃作用。结果表明，当磷腈和三嗪基团的摩尔比例为11: 5时，复配阻燃PLA复合材料的阻燃效果最好。（4）合成了一种原位掺杂纳米氧化锌的磷腈/三嗪双基分子（A4-d-ZnO），将其用于阻燃聚乳酸树脂，研究其对聚乳酸的阻燃性能和热性能的影响规律。实验结果表明, A4-d-ZnO在较低添加量下就能极大程度提高PLA树脂的阻燃效果，这是由于A4-d-ZnO在阻燃聚乳酸体系中发挥断链促滴落的阻燃机理。