合成革用聚氨酯-纳米SiO_2原位杂化涂层的制备及其透气、透湿性能研究

Nano-SiO_2 In-situ Hybrid Polyurethane Leather Coating with Enhanced Permeability

采用原位有机-无机杂化技术将SiO2颗粒引入合成革用聚氨酯涂层中，并对杂化涂层的截面形态、透气透湿性、孔径分布和比表面积进行了检测。结果表明：当SiO2的含量不高于1．5％时，原位生成的SiO2颗粒不仅在聚氨酯涂层中分布均匀，且其粒径被控制在70～150nm；由于有机聚氨酯和无机纳米SiO2颗粒间形成了相间孔隙，因此聚氨酯涂层的透气（氢气、氮气和氧气）、透湿性随纳米SiO2含量的提高而逐渐增加。当SiO2的含量超过1．5％时，原位生成的SiO2颗粒属微米级且团聚明显，其阻透作用将导致聚氨酯涂层透气、透湿性能的降低。本实验所制备的聚氨酯-纳米SiO2原位杂化涂层有望改善合成革产品的穿着舒适性和卫生性能。

A novel in-situ organic-inorganic nano hybrid technique combined with industrialized wet phase inversion coating-forming process was developed for the modification of polyurethane （PU） leather coating with nano-SiO2. During the wet phase inversion process, nano-SiO2 particles were in-situ generated synchronously as polyurethane resin coagulated. Scannir_g electron microscope （SEM） analysis indicated that when the SiO2concentration was limited within 1.5% , the size scale of in-situ generated nano-SiO2 particles ranged from 70 nm to 150 nm, which were well-separated and dispersed uniformly throughout the PU coating. After nano hybridization, extra mesopores, existed at the polymcr/nano-SiO2 interface, were detected in the PU coating by nitrogen adsorption/desorption experiment. The vapour permeability were correlated with enhanced gas （hydrogen, nitrogen and oxygen） and water vapor permeability, which could improve the wear comfort of the PU leather. Nevertheless, when the SiO2concentration was increased up to more than 1.5% , micro-SiO2particles and agglomerates dominated throughout the PU matrix, which obstructed mass transportation and lowered the permeability of the coating. Without disturbing established wet phase inversion coating-forming process in PU leather industry, the novel in-situ organic-inorganic nano hybrid technique developed in this study may be of great potential for producing PU leather with improved wear comfort on an industrial scale.