title: Dissolution of Wood Pulp in Aqueous NaOH/Urea Solution via Dilute Acid Pretreatment.
abstract: Wood pulps with certain amounts of lignin were successfully dissolved in aqueous NaOH/urea solution by subjecting them to the dilute acid pretreatment. After the acid hydrolysis, viscosity-average degree of polymerization (DPv) of the pulps decreased. The results revealed that both the DPv and lignin contents influenced the dissolved proportions of wood pulps. When they were not so high, the wood pulps could almost completely dissolve with dissolved proportions >90%. In particular, the acid-pretreated unbleached kraft pulp with DPv of about 500 and lignin content of 6.9% could dissolve in NaOH/urea solvent and achieve a maximum pulp concentration of 4 wt % in the obtained lignocellulose solution. Moreover, the acid-pretreated bleached thermomechanical pulp with a high lignin content of 14.2% also almost completely dissolved. The lignocellulose films prepared from these wood pulp/NaOH/urea solutions exhibited good transparency and bendability, thus maybe promising as new biobased materials.
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Zhuqun
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Quanling
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kuga
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsumoto
mesh_terms: D000143:Acids / Q000737:chemistry; D001709:Biotechnology; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry; D012995:Solubility; D014508:Urea / Q000737:chemistry; D014783:Viscosity; D014934:Wood / Q000737:chemistry*
chemical_list: D000143:Acids; C036909:lignocellulose; D012972:Sodium Hydroxide; D014508:Urea; D008031:Lignin
keywords: degree of polymerization; dilute acid treatment; dissolved proportion; lignocellulose