紫外光固化的聚氨酯－丙烯酸酯－纤维素复合膜

Polyurethane-Acrylate-Cellulose Composite Film Cured by UV Irradiation

再生纤维素膜（甘蔗渣浆制）表面直接用紫外光固化聚氨酯－丙烯酸酯制备出防水性复合膜。由红外光谱和扫描电镜研究了复合膜的结构。同时，测定了膜的防水性、力学性能、水汽透过性和尺寸稳定性。实验结果表明，当聚氨酯：丙烯酸酯为４０：５５（质量比），在４００Ｗ紫外光下固化５ｍｉｎ制得的复合膜具有致密的表面结构和较好的性能，该膜经水浸泡后其断裂强度可达干膜的９０％，浸水收缩率和膨胀率均小于２．５％，水汽渗透量仅为再生纤维素膜的１／４。由此表明复合膜的防水性和尺寸稳定性明显提高。此外，该复合膜在可见光区的透光率在８０％～９０％之间，而且对紫外光有屏蔽作用。

A composite film with water-resistance was prepared by curing polyurethane-acry-late on regenerated cellulose film (from bagasse pulp) under UV-irradiation. The structures of films were studied by IR and SEM. The water-resistance, mechanical properties, water vapor permeability and size stability of the films were measured.The experimental results showed that when polyurethane/arcylate is 40:55 by mass,the composite film prepared under 400 W UV irradiation for 5 min possesses dense surface structure and good mechanical properties. After being soaked in water,the tensile strength retained 90% that of dry film,the shrinkage and swelling were less than 2. 5%,and the water vapor permeability was a quarter of that of uncured cellulose film. The water-resistance and size stability of the composite film were improved significantly.In addition,its transmittance in visible range is 80%￣90% and it can shield UV light.