生物质化学工程2018，Vol.52Issue(3)：16-22,7.DOI:10.3969/j.issn.1673-5854.2018.03.003
NaOH/尿素冷冻活化木材纤维的工艺研究
Activation Processes of Wood Fiber Under Freezing by NaOH/urea Aqueous Solution
摘要
Abstract
The wood fiber was activated by sodium hydroxide/urea mixed aqueous solution under freezing treatment.The freezing activation effect of wood fiber was characterized by measuring the mechanical properties of the self-bonding fiberboard hot-pressed with activated wood fiber and implementing the analysis of Fourier tansform infrared spectroscopy and X-ray diffraction.The experimental results showed that the sodium hydroxide/urea mixed aqueous solution had a certain activation effect on the wood fiber under freezing treatment.The optimized activated process was described as the mass ratio of total sodium hydroxide and urea (the mass ratio of sodium hydroxide to urea 7:12) to wood fiber 1:12, freezing temperature -15℃, freezing time 1.0 h, and wood fiber moisture content 20％.The static bending strength and internal bonding strength of fibreboard prepared with wood fiber freezing-activated by sodium hydroxide/urea mixed aqueous solution increased from 32.16 and 0.29 MPa to 45.53 and 1.21 MPa, and the water absorption rate and the thickness swelling rate decreased from 53.95％and 22.57％to 43.62％and 10.34％respectively compared to those of the unactivated wood fiber.Microscopic characterization by Fourier tansform infrared spectroscopy and X-ray diffraction showed that the hydrogen bonding structure of cellulose in the wood fiber was destroyed under the freezing activation treatment with sodium hydroxide/urea mixed solution, the expansion of cellulose I lattice was promoted and a new crystalline modification was produced, which reduced the degree of molecular association and consequently enhanced the hydroxyl activity of the wood fiber surface.关键词
木材纤维/无胶胶合/冷冻活化/氢氧化钠/尿素Key words
wood fiber/self-bonding/freezing activation/sodium hydroxide/urea分类
化学化工引用本文复制引用
马盼盼,陈冰玉,邸明伟..NaOH/尿素冷冻活化木材纤维的工艺研究[J].生物质化学工程,2018,52(3):16-22,7.基金项目
国家林业公益性行业科研专项(201504501) （201504501）
国家自然科学基金资助项目(31670567) （31670567）
