聚硅氧烷改性聚氨酯纤维基防水透湿膜的可控制备及传质机制研究

Waterproof and breathable membranes are critical for fabricating protective garments, such as outdoor jackets and combat uniform; however, synchronously improving of the waterproofness breathability and mechanical properties of the membranes had became an important research area. Therefore, in this work, we plan to synthesize a liner polyurethane which modified by polysiloxane through step synthesis process, and LSiPU fibrous membranes would be fabricated via electrospinning progress. The detailed research process listed as follows, investigating the influence of synthesis route and conditions of polymerization on the molecular structure and molecular mass of LSiPU would be investigated, obtaining the optimum synthesis conditions of LSiPU with excellent hydrophobicity and spinnability, studying the effect of solutions characteristic and process parameters on the phase separation of polymer solution jet, exploring the self-enrichment behavior of polysiloxane chains onto the surface of LSiPU fibers, establishing the controllable fabrication method of LSiPU fibers with designed structure and wettability, evaluating the effect of fibrous frame structure on mechanical performance of the fibrous membranes, illuminating the relationship between porous structure characteristic and waterproof and breathable performances of the fibrous membranes, establishing the collaborative optimization mechanism of the waterproofness, breathability and mechanical strength. The final target of this work is to obtain LSiPU fibrous membranes with tensile strength over 20MPa，hydrostatic pressure over 150kPa and water vapor transmission rate over 10000g/(m2·d).

兼具防水和透湿功能的膜材料是制造冲锋衣、野战军服等防护服装的核心材料，但如何同步提高膜材料的耐水渗透性、透湿性及力学性能是防水透湿膜材料的重要研究方向。为此，本项目拟逐步聚合法合成一种线形聚硅氧烷改性聚氨酯（LSiPU），考察聚合反应路线及反应条件与LSiPU分子结构及相对分子质量间的内在关联，确立具有优异疏水性和可纺性的LSiPU的最佳合成条件；采用静电纺丝技术制备LSiPU纤维膜，研究纺丝原液性质及纺丝环境参数对聚合物溶液射流相分离过程的影响规律，探索聚硅氧烷链段在纤维表面自富集行为特点，明晰纤维膜的成型边界条件及纤维表面润湿性的调控规律，确立LSiPU纤维膜的可控制备方法；考察纤维框架结构对力学性能的影响规律，揭示纤维膜内部孔道结构特征与防水透湿性能间的参数关联，最终实现LSiPU纤维膜拉伸强度>20MPa、耐水渗透压力>150kPa、透湿通量>10000g/(m2·d)的目标。

兼具防水和透湿功能的膜材料是制造冲锋衣、野战军服等防护服装的核心材料，其不仅能抵御雨雪浸湿造成的冻伤侵害，还能有效排出人体产生的湿汽，避免产生粘湿、闷热等不适感，但如何同步提高膜材料的耐水渗透性、透湿性及力学性能仍是该领域存在的巨大难题。本课题“聚硅氧烷改性聚氨酯纤维基防水透湿膜的可控制备及传质机制研究”旨在明晰纤维膜的成型边界条件及纤维表面润湿性的调控规律，揭示纤维膜内部孔道结构特征与防水透湿性能间的参数关联，实现纤维膜的可控制备及其在防护服装领域的实际应用。从2020年初开始到2022年末这三年的时间里，开展了大量的实验研究工作：我们以硅烷改性/醇溶性/水性环保聚氨酯为原料，系统考察了纺丝原液性质及纺丝环境参数对聚合物溶液射流相分离过程的影响规律，探索了聚硅氧烷链段在纤维表面自富集行为特点，明晰了纤维膜的成型边界条件及纤维表面润湿性的调控规律，为实现网状互粘结构聚氨酯防水透湿纤维膜的可控制备提供了实验基础；基于菲克扩散定律和杨氏拉普拉斯方程，确立了获得最佳防水透湿性能的聚氨酯纳米纤维膜成型条件，阐明了汽/液介质在纤维膜互联多孔通道中的输运机制，对聚氨酯纳米纤维防水透湿膜的结构设计提供了理论指导；通过系统考察纳米纤维膜微观结构与力学性能的构效关系，实现了力学性能与防水透湿性的协同调控，成功制备出了兼具良好防水透湿性及力学性能的聚氨酯纳米纤维膜，最终实现了拉伸强度>20MPa、耐水渗透压力>150kPa、透湿通量>10000g/(m2·d)的目标。项目执行期间共培养博士2名，硕士4名。发表学术论文7篇，申请发明专利3项，获授权专利3项。本课题的完成对探究纳米纤维膜防水透湿性能与力学性能的协同优化机制、实现纳米纤维膜在防护服装领域的特效应用具有重要意义。