仿星型拓扑几何结构聚氨酯/聚二甲基硅氧烷防水透湿膜制备与性能

Preparation and performance of polyurethane/polydimethylsiloxane waterproof and moisture permeable membrane with star like topological geometry structure

为提高纳米纤维膜的防水性并探究膜表面微观结构对膜性能的影响机制,采用高可纺性的聚氨酯(PU)和无氟、低表面能的聚二甲基硅氧烷(PDMS)为原料,通过静电纺丝法制备了PU/PDMS纳米纤维膜,然后在该纤维膜基材上采用静电喷雾法沉积PU/PDMS微颗粒得到对环境友好的防水透湿膜,对其形貌、防水性能、透气透湿性能和力学性能进行测试与分析。结果表明:静电喷雾引入的微颗粒之间以超细纤维连接构成了仿星型拓扑几何结构,与PU/PDMS纳米纤维基材发生物理粘连,形成了一种稳定的膜结构,其防水性能与力学性能均得到一定程度改善;当静电喷雾纺丝溶液中PU/PDMS质量分数为6%,喷雾时间为2 h时,防水透湿膜表现出最优异的防水性,其静态水接触角达到149.1°,透湿率为5566.7 g/(m^(2)·d),透气率为11.50 mm/s,断裂强度为8.22 MPa,断裂伸长率为247.1%。

In order to study the waterproof properties of nanofiber membranes and explore the mechanism of the influence of the microstructure of the membrane surface on the membrane properties,polyure-thane(PU)/polydimethylsiloxane(PDMS)nanofiber membranes were prepared by electrospinning method with high spinning PU and fluorinated low surface energy PDMS as raw materials.The PU/PDMS particles were deposited by electrostatic spray on the fiber membrane substrate,leading to the creation of an environment-friendly waterproof and moisture permeable membrane.The morphology,waterproof properties,air and moisture permeability and mechanical properties were tested and analyzed.The results showed that the superfine fiber links formed by electrostatic spray formed a star like topological structure,and formed a stable membrane structure with the PU/PDMS nanofiber substrate,with improved waterproof and mechanical properties.When the electrostatic spraying PU/PDMS mass fraction is 6%and the time is 2 h,the nanofiber membrane shows the best water repellency.Under this conditions,the static contact angle of the water reaches 149.1°,the moisture permeability is 5566.7 g/(m^(2)·d),the air permeability is 11.50 mm/s,the breaking strength is 8.22 MPa,and the elongation at break is 247.1%.