Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Biomacromolecules. 2011 Jul 11;12(7):2766-71. doi: 10.1021/bm200766v. Epub 2011 Jun 21.
Transparent and bendable regenerated cellulose films prepared from aqueous alkali (NaOH or LiOH)/urea (AU) solutions exhibit high oxygen barrier properties, which are superior to those of conventional cellophane, poly(vinylidene chloride), and poly(vinyl alcohol). Series of AU cellulose films are prepared from different cellulose sources (cotton linters, microcrystalline cellulose powder, and softwood bleached kraft pulp) for different dissolution and regeneration conditions. The oxygen permeabilities of these AU cellulose films vary widely from 0.003 to 0.03 mL μm m(-2) day(-1) kPa(-1) at 0% relative humidity depending on the conditions used to prepare the films. The lowest oxygen permeability is achieved for the AU film prepared from 6 wt % cellulose solution by regeneration with acetone at 0 °C. The oxygen permeabilities of the AU cellulose films are negatively correlated with their densities, and AU films prepared from solutions with high cellulose concentrations by regeneration in a solvent at low temperatures generally have low oxygen permeabilities. The AU cellulose films are, therefore, promising biobased packaging materials with high-oxygen barrier properties.
由水基碱（氢氧化钠或氢氧化锂）/尿素（AU）溶液制备的透明且可弯曲的再生纤维素膜具有优异的氧气阻隔性能，优于常规的赛璐玢、聚（偏二氯乙烯）和聚乙烯醇。一系列 AU 纤维素膜是由不同的纤维素来源（棉绒、微晶纤维素粉末和软木漂白牛皮纸浆）在不同的溶解和再生条件下制备的。这些 AU 纤维素膜的氧气透过率在 0%相对湿度下根据制备膜的条件从 0.003 到 0.03 mL μm m(-2) day(-1) kPa(-1) 变化很大。通过在 0°C 下用丙酮再生由 6wt%纤维素溶液制备的 AU 膜可获得最低的氧气透过率。AU 纤维素膜的氧气透过率与其密度呈负相关，并且由高浓度纤维素溶液在低温下用溶剂再生制备的 AU 膜通常具有低的氧气透过率。因此，AU 纤维素膜是具有高氧气阻隔性能的有前途的生物基包装材料。
