生物基聚酰胺56纤维聚集态结构与性能研究

As a new polyamide material, bio-based PA 56 has not been produced in scale, and the research basis is very weak. In this project, aiming at the critical scientific problems in the preparation of PA 56 fiber and in the processing of textile materials, the formation and evolution of the aggregation and microstructure in PA56 fiber were studied in the spinning process. The relationship between the formation and evolution of fiber aggregation and microstructure and spinning parameters was studied. The mechanical properties of PA56 fibers were discussed depending on the different aggregation and microstructure in fibers. And the regulation method for the mechanical properties of PA56 fibers was established. This project also studied the dyeing and flame resistance properties of PA 56 fiber and their correlation with the aggregation and microstructure of the fiber, which was helpful to elucidate the dyeing mechanism and flame resistance. There will provide scientific basis and theoretical support for the development in the industrialization of the bio-based PA 56 fiber. The implementation of this project will promote the development of the relevant fields such as PA 56 resins, fibers and fabrics, which have an independent intellectual property rights in China. It is of great social value to the industrial progress of basic raw materials and their products. It is of large strategic significance to the original technology reserve of key strategic raw materials for military equipment.

生物基PA56作为一种全新的聚酰胺材料，尚未实现规模化生产，研究基础十分薄弱。本项目针对PA56纤维制备和纺织材料加工过程中急需解决的关键科学问题，开展生物基PA56纺丝过程中纤维聚集态结构和微观结构的形成、演变及纤维性能等方面的研究。研究纤维聚集态结构和微观结构的形成、演变过程与纺丝工艺参数的相关性；探讨纤维聚集态结构和微观结构与机械性能的相互关系，建立性能的调控方法。研究PA56纤维的染色性能和本征阻燃性能及其与纤维聚集态结构和微观结构的相关性，阐明其染色机理和本征阻燃性能机理，为生物基PA56纤维的产业化技术发展提供科学依据和理论支撑。本项目的实施对我国具有独立知识产权的生物基PA56树脂、纤维和织物等相关产业发展具有推动作用，对我国基础原材料及其制品的产业进步和军事装备关键战略原材料原创性技术储备具有重要的社会价值和战略意义。

生物基聚酰胺（PA）56纤维是我国具有自主知识产权的颠覆性纤维新材料，针对PA56聚合、纤维制备及结构性能等基础和应用的科学问题，围绕聚合物的多级结构-流变性能-纺丝加工条件-纤维性能之间的相互关系开展了系统研究。.通过研究PA56树脂的流变性能及其分子结构和温度的关系，发现PA56的熔点和玻璃化温度随分子量增加而增加，结晶速率、冷却结晶温度和结晶度随着分子量增加而降低。PA56结晶有类α相和γ相两个晶型，降温过程Brill转变过程不可逆，其根本原因在于其构成氢键长短不同。研究表明，PA56最优的纺丝温度270-290°C，PA56粘度指数大于120 ml/g时可纺性好。.系统研究了低速纺牵两步法、高速纺牵一步法和高速预取向纺丝法在PA56纤维制备过程中结构-性能间关系，通过优化不同纺丝方法的工艺参数，明晰了牵伸倍数、牵伸温度等参数对强度的影响规律，结果表明：纺丝-牵伸一步工艺较优，较易调控聚集态结构和机械性能，发明了纺丝-牵伸-定型一步高速纺丝方法。.研究建立了纺丝工艺参数与PA56纤维结构和性能影响规律，在拉伸过程中，PA56氢键的重新构筑，无定形相转变为类α晶型，分子链取向增加，结晶度随着片晶厚度的增加而增加；在150-210℃范围内，随着退火温度的升高，纤维的结晶度和取向增加，PA56纤维最优的退火温度在170℃左右；纺牵一步法制备的PA56纤维，温度升高纤维强度增加，断裂伸长率降低。.PA56纤维的结构决定了其独有的染色、阻燃性能。PA56与PA6和PA66纤维对比研究表明，PA56具有低温可染、染色速率快、上染率高的特性，原因在于PA56纤维的强极性导致了纤维和水或极性染料的亲和力增强，PA56较高的无定型区比例，使得染色自由体积较大，染色位点增多，使染料更容易吸附并扩散进入纤维内部。PA56本征阻燃性能优于PA66和PA6，原因在于纤维表面显示特殊的富氮和富碳特征，且PA56的裂解产物中含有较稳定的含氮环状化合物。.生物基PA56纤维基础科学问题研究，揭示了其独特性能与结构内在关系，为PA56纤维的高效纺丝和绿色应用新技术的开发奠定了理论基础，为产业化和高性能化发展提供了技术支撑。