木材溶剂液化技术及其在制备高分子材料中的应用

木质材料经过热化学液化,可进一步制备酚醛树脂、聚氨酯等高分子材料.本文介绍了木材液化技术制备高分子材料的发展状况,包括液化方法、木材主成分的液化机理以及液化生成物的应用,指出在木材液化反应机理、液化产物的利用和最佳液化工艺的开发等方面尚有待进一步研究,并提出充分利用木材的生物降解性,开发木材液化物与其他材料复合的新型高分子材料具有广泛的前景.     

木材液化及其在高分子材料中的应用

木材通过液化可转化为具有反应活性的液态产物,进一步反应可以制备胶粘剂、聚氨酯材料等新型高分子材料。文章从方法、机理以及其产物在制备高分子材料等方面对木材液化的研究进展进行了评述。     

未经化学改性的木材液化研究进展

木材是固态的天然高分子材料,通过液化可将其转化为具有反应活性的液态分子,该技术对充分利用自然界中可再生资源具有重要的意义。综述了未经化学改性的木材液化的研究进展,并对木材液化技术存在的问题以及木材液化的发展趋势进行简要分析。     

木材中的纳米分形木质纤维及碳素纤维材料的制备

利用分形理论构建了木材细胞壁中的分形木质纤维,并计算了分形木质纤维S1层和S2层的扭曲分形维数,指出木材中具有纳米尺度的纤维结构;同时,以木材液化和纳米纺丝技术为基础,提出了木材苯酚液化产物制备碳素纤维材料的构思和技术路线,为解决木材纳米、微米材料的制备提出了新思路。     

木材的超临界气化和液化与木本生物质能源转化

木材是生物质能源的主体,开发木质(生物质)能源也是我国木材工业一个重要内容。木材的超临界流体气化和液化是大规模利用木质生物能的有效途径,具有良好的经济前景和环保优势。介绍木材的超临界流体气化和液化的基本原理和研究进展,应用木材超临界热解和气化制氢,对生物质能源的开发和森林资源的高效利用具有重要意义。     

木质生物材料液化的研究现状及应用

木质生物材料是固态的天然高分子材料,通过液化可将其转化为具有反应活性的液态分子,进一步可制备新型高分子材料如胶黏剂、注模塑料、泡沫塑料、纤维材料等,具有广泛的应用前景,是木质生物材料化学和木质生物材料利用技术新开辟的研究领域。文章综述了近年来生物质材料液化技术在国内外的研究现状及应用。     

纤维类生物质的溶剂液化及在聚氨酯材料中的应用

纤维类生物质是固态的天然高分子材料,用多元醇等有机溶剂能将难溶、难熔的纤维类生物材料转化为具有反应活性的液态物质,进一步可制备新型高分子材料如胶粘剂、泡沫塑料等,具有广泛的应用前景。文章主要总结了生物质多元醇液化技术的发展状况,包括溶剂液化的方法,液化机理以及液化产物在聚氨酯中的应用,并对我国该领域研究存在的问题、产业化发展提出了一些看法。     

木材液化技术的研究进展

综述了近30年来国内外木材液化技术的研究进展,简介了以酸或碱为催化剂、无催化剂和超临界萃取等木材液化的主要方法,木材液化技术对充分利用自然界中可再生资源、降低环境污染具有重要的意义.     

木材乙基化改性及其溶液化研究

研究了木材乙基化改性反应及乙基化木材在某些溶剂中的溶液化行为。探讨了硫酸H乙酯和NaOH用量、反应温度及时间对木材乙基化反应的影响。在盐酸催化剂作用下增重率（WPG）18％以上的乙基化木材可在110℃溶于乙二醇中；而在双酚A一乙酸乙酯中，乙基化木材的WPG只需大于6％，即能在更温和条件（80℃）下溶液化。获得的溶液可作为化工原料用于制备以木材主成分为骨架的新型高分子材料。     

木质生物材料多元醇液化及其在聚氨酯中的应用

液化技术是近年来生物质材料高效增值利用领域的研究热点,用多元醇等有机溶剂能将难溶、难熔的木质生物材料转化为可流动、具有反应活性的液态物质,拓宽了木材的应用领域。液化产物可作为合成高分子树脂的原料,能部分替代来源于石化产品的聚酯或聚醚多元醇。综述了木质材料多元醇的液化方法、液化机理及液化产物在聚氨酯中的应用。     

A KINETIC STUDY OF SULFURIC ACID-CATALYZED LIQUEFACTION OF WOOD INTO PHENOL

The powders of monarch birch wood (Betula maximowiczina Regel) were liquefied into phenol using sulfuric acid as a catalyst at various temperatures and reaction times. Typical kinetic parameters of the degrading reaction of wood in the presence of phenol and the acid were determined using typical kinetic models. In addition, the activation parameters of the liquefaction of wood were determined according to transition-state theory. The results of showed percent liquefied wood that about 100% of the wood could be liquefied into phenol at a temperature of 150°C for about 2 h. However, about 68% of phenol was found to react mainly with wood components along with sulfuric acid and phenol itself. The kinetic studies showed that the liquefaction of wood into phenol using sulfuric acid obeyed a bimolecular type second-order reaction and Arrhenius law. The activation energy of the liquefaction was 68.5 kJ mol^-1. Furthermore, the findings related with activation enthalpy showed that the liquefaction of wood possessed a primarily endothermic reaction nature.     

A KINETIC STUDY OF SULFURIC ACID-CATALYZED LIQUEFACTION OF WOOD INTO PHENOL

The powders of monarch birch wood (Betula maximowiczina Regel) were liquefied into phenol using sulfuric acid as a catalyst at various temperatures and reaction times. Typical kinetic parameters of the degrading reaction of wood in the presence of phenol and the acid were determined using typical kinetic models. In addition, the activation parameters of the liquefaction of wood were determined according to transition-state theory. The results of showed percent liquefied wood that about 100% of the wood could be liquefied into phenol at a temperature of 150°C for about 2 h. However, about 68% of phenol was found to react mainly with wood components along with sulfuric acid and phenol itself. The kinetic studies showed that the liquefaction of wood into phenol using sulfuric acid obeyed a bimolecular type second-order reaction and Arrhenius law. The activation energy of the liquefaction was 68.5 kJ mol^?1. Furthermore, the findings related with activation enthalpy showed that the liquefaction of wood possessed a primarily endothermic reaction nature.     

Influence of wood species on the properties of biopolyurethane prepared from liquefied wood with residue

Biopolyurethane prepared from liquefied wood with the residue of the liquefied wood product was investigated in this article. Previous results indicated that the residue of the liquefaction product was composed mostly of compounds originated from lignin. The chemical structures of lignin in softwood and hardwood are different. The influence of soft‐ and hardwood species on the chemical structure and mechanical properties of biopolyurethane prepared from liquefied wood with residue was investigated by tensile testing and Fourier transform infrared spectroscopy. The experimental results showed that the liquefaction of softwood occurs within a shorter time than that of hardwood and the biopolyurethane prepared from softwood was harder than that prepared from hardwood, which suggests that the properties of the liquefaction product and biopolyurethane are influenced by the chemical structure of the lignin. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

木质生物质的液化及其产物的高效利用研究进展

对国内外木质生物质原料的液化及液化产物的高效利用研究的现状及进展进行了概述,讨论了木质生物质原料液化及其产物的应用前景,重点讨论了不同木质生物质原料液化过程中的主要影响因素,并分析了具有代表性的液化物结构特点,具体介绍了一些液化产物实际应用特别是在胶黏剂制备方面应用的典型实例。对我国该领域研究存在的问题、产业化发展提出了一些看法。     

Investigation of liquefied wood residues based on cellulose,hemicellulose, and lignin

Chinese eucalyptus was subjected to a liquefaction process using glycerol/ethylene glycol (EG) as liquefaction solvent. The effects of various liquefaction conditions, including reaction time, liquefaction temperature, acid concentration, and liquor ratio on the chemical composition of liquefied wood residues were studied. The results showed that the whole liquefaction process took place in two stages, the liquefaction yield of wood depended on the reaction temperature, acid concentration and liquor ratio. With increased acid concentration the liquefaction yield, acid‐insoluble lignin, and hemicellulose content of the residues were increased, and the relative content of cellulose was decreased. Fourier transform infrared (FT‐IR) analyses of the residues showed that hemicellulose and lignin were almost decomposed at the initial stages of reaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Molecular weights and molecular weight distributions of liquefied wood obtained by acid-catalyzed phenolysis

By means of gel permeation chromatography analysis, the molecular weights and molecular weight distributions of liquefied wood obtained under various liquefaction conditions and species of catalysts were investigated in order to trace the change in the structural characteristics of the liquefied wood. The results indicated that during the liquefaction reaction, wood components were subjected to decomposition, phenolation, and recondensation. The intensities of these reactions depended greatly on the reaction conditions and the species of catalysts, and their competing result determined the structural characteristics of the resulting liquefied wood. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 351–357, 1997     

Polyurethane coatings from liquefied wood containing remains of a copper‐, chromium‐, and boron‐based wood preservative

Preparation of polyurethane wood coatings based on copper‐, chromium‐, and boron (CCB) containing liquefied wood was performed, as an alternative way to manage postconsumed preservative‐contaminated wood. Additionally, we examined the possibility of improvement of selected properties of the liquefied wood‐based coatings by an addition of silica nanoparticles. The constituents of the CCB wood preservative do not exhibit an influence on a liquefaction process and on composition of the liquefied mixture. CCB also does not affect curing of the formulations containing liquefied wood and an isocyanate‐type hardener. Furthermore, influence of CCB on adhesion strength of liquefied wood‐based coatings on a wooden substrate, their hardness, and resistance to scratching and to water, acetone, and alcohol, is not exhibited. However, apart from these, from the applicative point of view, positive results, any improvement of the coating properties by the addition of silica nanoparticles is not shown. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40865.