title: Transparent cellulose films with high gas barrier properties fabricated from aqueous alkali/urea solutions.
abstract: 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.
authors.affiliation: Department of Biomaterial Sciences, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Quanling
authors.initials: Q
authors.lastname: Yang
authors.forename: Hayaka
authors.initials: H
authors.lastname: Fukuzumi
authors.forename: Tsuguyuki
authors.initials: T
authors.lastname: Saito
authors.forename: Akira
authors.initials: A
authors.lastname: Isogai
authors.forename: Lina
authors.initials: L
authors.lastname: Zhang
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D003368:Gossypium / Q000737:chemistry; D018020:Lithium Compounds / Q000737:chemistry*; D008567:Membranes, Artificial; D010100:Oxygen / Q000737:chemistry*; D010539:Permeability; D012972:Sodium Hydroxide / Q000737:chemistry*; D012996:Solutions; D014508:Urea / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D018020:Lithium Compounds; D008567:Membranes, Artificial; D012996:Solutions; D014867:Water; D012972:Sodium Hydroxide; D014508:Urea; D002482:Cellulose; C028467:lithium hydroxide; D010100:Oxygen