水性聚氨酯膜的制备及在超纤革中的应用

以水性聚氨酯(WPU)为聚合物,采用物理机械发泡的方法制备WPU膜,系统研究了成膜温度对WPU膜形态结构和性能的影响规律。结果表明,当成膜温度低于100℃时,所制备WPU膜的泡孔密度、表面孔孔径、平均孔径、结晶度、透气量、透湿率、断裂强度和断裂伸长率等均随成膜温度的升高而增大。其中,当成膜温度为80℃时,膜具有最佳的性能。随着成膜温度进一步升高,膜的表面出现裂纹,透气量和透湿率增加,而断裂强度和断裂伸长率显著减小。在此基础上,经干法移膜技术制备的WPU超纤革达到了成品等级的A类产品。

Preparation of Waterborne Polyurethane Membrane and Its Applications in Microfiber Synthetic Leather

The waterborne polyurethane (WPU) membrane using WPU as polymer was prepared through physical-mechanical foaming.The effects of membrane-forming temperature on the structure and performance of WPU membranes were investigated.The results show that the foam density,surface pore size,mean pore size,crystallinity,air permeability,water vapor permeability,tensile strength and elongation at break of the obtained WPU membrane increase with an increase from 40 ℃ to 80 ℃ in membrane-forming temperature.When membraneforming temperature is 80 ℃,the permeability of WPU membrane obtained is optimal.Further,the WPU membranes with the increase of membrane-forming temperature exhibit crack structure.The air permeability and water vapor permeability of the obtained WPU membrane increase with the increase of membrane-forming temperature,and the tensile strength and elongation at break observably decrease with the increase of membraneforming temperature.On this basis,the WPU microfiber synthetic leather made by dry process has reached the level of A.