原位聚合过程中基于三聚氰胺氰尿酸盐形成并构筑协效体系的阻燃聚酰胺纤维研究

Development of manufacturing process for making flame retardant polyamide fiber is urgently needed. The suitable flame retardant, introduced way and interaction with polyamide are key point of making flame retardant polyamide fiber. In this project, melamine cyanurate will be chosen as the flame retardant, and the cyanuric acid/hexane diamine salt, melamine/adipic acid salt will be added in the polymerization process of polyamide. This means that the synthesis of polyamide and formation of melamine cyanurate will be combined together by in situ polymerization, which will be propitious to obtain the good spinnability flame retardant polyamide fiber. The introduced way, formation, distribution of melamine cyanurate in the system,the interaction of melamine cyanurate with the synthesis of polyamide, the polymerization mechanism of polyamide in this system，and the action mechanism of melamine cyanurate with the properties of flame retardant all will be researched in this project. Furthermore, according to the principle of nitrogen-phosphorus, nitrogen-silicon, nitrogen-phosphorus-silicon synergistic effect to design and select the synergistic flame retardants, the introduced way of them, the influence on polyamide synthesis and the action mechanism with flame retardant will be investigated. In the last, the effect and relationship of flame retardant system with the properties of anti-melt dripping will also be studied. The implementation of the project will enrich multicomponent polymer system theories and serve as foundational knowledge for production of flame retardant polyamide fiber.

无卤阻燃聚酰胺纤维的研究一直未见突破，合适阻燃体系、引入方式及与聚酰胺的相互作用是关键。课题选择三聚氰胺氰尿酸盐（MCA）为阻燃剂，在聚酰胺聚合体系中添加等摩尔的己二酸三聚氰胺盐和氰尿酸己二胺盐，利用原位聚合成形原理将聚酰胺合成和MCA形成有机地结合在一起，以获得具有阻燃特性且可纺性能良好的MCA/聚酰胺。课题将主要研究单体盐的制备调控机理，MCA在聚合过程中引入、形成机理及与聚酰胺大分子合成反应的相互作用关系；分析阻燃组分在体系中的状态和分布，总结体系中聚酰胺合成机理，揭示MCA对聚酰胺纤维的阻燃机理。在此基础上，按照氮磷、氮硅、氮磷硅等协效作用原则设计筛选协效阻燃剂，研究其在原位聚合中引入对聚酰胺合成和性能的影响、与MCA相互协同作用机理等。最后还将探索阻燃体系构筑在影响阻燃性能之余对其抗熔滴性能的作用。项目实施将有利于建立阻燃聚酰胺纤维制备新方法和新途径，丰富多相与多组分体系的理论。

纤维制品通常轻薄、比表面积大，极易引燃，同时由于纤维直径细、纺丝速度快致其制备过程控制非常苛刻，因此相较塑料和橡胶，纤维的阻燃改性尤显重要和困难。聚酰胺纤维具有力学性能好、密度相对低、吸湿相对高等特性，在民用、工程用和军警用等领域有不可替代的应用，但阻燃聚酰胺纤维的研发一直未见突破。本课题对阻燃聚酰胺纤维的构筑方法及其阻燃机理展开研究，以丰富聚酰胺纤维创新的理论基础。课题实施过程中分别通过自组装法、单体法和直接法将三聚氰胺氰尿酸盐（MCA）经原位聚合体系引入聚酰胺中，利用TG、DSC、SEM、极限氧指数、垂直燃烧测试等表征阻燃聚酰胺及纤维的结构性能与阻燃机理。结果表明，MCA与聚酰胺具有一定相容性，阻燃聚酰胺及纤维的力学性能满足后续加工要求，极限氧指数和垂直燃烧UL94可达30%以上和V-0级，MCA在阻燃聚酰胺中以气相阻燃机理为主。在此基础，进一步研究成纤聚酰胺用反应型阻燃剂，制备具有长效阻燃特征的聚酰胺。结果表明，以DOPO及其衍生物为代表的阻燃剂所制备的阻燃聚酰胺纤维具有良好阻燃效果，极限氧指数和垂直燃烧UL94可达28%以上和V-0级，兼具气相阻燃机理和凝聚相阻燃机理。