Effects of phosphoric acid on liquefaction of wood in phenol and optimum liquefaction processing parameters

To clarify the influencing factors of liquefaction of wood in phenol using phosphoric acid as a catalyst and get its liquefaction technology, a study on the liquefaction technology of Chinese fir (Cunninghamia lanceolata) and poplar (triploid Populus tomentosa Carr) under different conditions was conducted. The results indicate that the residue rate decreases with the increase of liquefaction temperature, liquefaction time, catalyst content or liquid ratio. It is also found that the optimum condition of liquefaction for poplar is estimated as: the reaction temperature of 180 ℃, the reaction time of 2.5 h, liquid ratio (phenol/wood ratio)of 4.5 and catalyst content of 8%, and 4.2% residue rate could be obtained. Under the processing parameters of temperature 180 ℃, the reaction time of 2.5 h, liquid ratio (phenol/wood ratio) of 4 and catalyst content of 10%, the residue rate of Chinese fir can reach 5.6%.     

马尾松木材化学组分的遗传控制及对木材育种的意义

本文利用 1 3年生马尾松子代测定林的 2 0个自由授粉家系的木材试样 ,着重研究木材化学组分的遗传学问题。研究结果表明 ,木材化学组分、基本密度和生长性状在家系间的差异都达到了极显著水平 ,并受中等至强度的遗传控制。在 6个木材化学组分中 ,灰分、戊聚糖和 1 %NaOH抽出物含量的遗传力较高 ,木质素、综纤维素和热水抽出物含量的遗传力稍低。生长性状与木材密度呈显著的负相关 ,而与木材化学组分相关性很小 ,似相互独立。遗传相关认为灰分和热水抽出物含量可分别作为综纤维素和木质素的间接选择指标。由于综纤维素和木质素含量在家系间的绝对差异较小 ,仅为 2 %～ 3% ,对选育的实际意义不大。可选择综纤维素含量高的优株进行无性繁殖加以利用     

人工林米老排木材化学成分及其在树干高度上的变异

采用我国木材化学成分分析国家标准,对人工林米老排木材化学成分进行了测定和研究分析.结果表明:人工林米老排木材冷水抽提物含量和热水抽提物含量分别为2.67%和3.12%,1%NaOH抽提物含量为17.08%,纤维素含量为47.49%,综纤维素含量为80.42%,木素含量为28.80%,pH值为5.44;木材冷水抽提物和综纤维素含量在树干的不同高度上略有差异,但方差分析检验,差异不显著,热水抽提物、1%NaOH抽提物、纤维素和木素含量在树干的不同高度上差异显著,达到1%显著性水平;由树基往上,热水抽提物含量略呈两端高、中间低的趋势,冷水抽提物、1%NaOH抽提物和木素的含量逐渐降低,综纤维素含量和木材pH值逐渐升高;纤维素含量在树干上的分布规律为中间高、两端低,而且从树干中部往上的降低幅度较大.     

Chemical reactivity of heat-treated wood

Chemical reactivity of heat-treated wood was compared with that of untreated wood. For this purpose, heat-treated pine or beech sawdust was reacted with different carboxylic acid anhydrides in pyridine or with phenyl isocyanate in dimethyl formamide. Compared to controls, weight gains obtained with heat-treated sawdust are smaller showing a lower chemical reactivity. FTIR analyses of lignin and holocellulose fractions, isolated after acidic hydrolysis of polysaccharides or delignification with sodium chlorite, indicate that both components are involved in the reactions. Compared to lignin, holocellulose exhibits important infrared absorptions of about 1,730 cm⁻¹, characteristic of ester or urethane linkages formed. Lower reactivity of heat-treated sawdust is explained by the decrease in free reactive hydroxyl groups in holocellulose due to the thermal degradation of hemicelluloses, considered more reactive than cellulose.     

Effects of inorganic acid catalysts on liquefaction of wood in phenol

In order to obtain the effects of acid catalysts on wood liquefaction in phenol, we investigated the liquefaction of wood powder from Chinese fir (Cunninghamia lanceolata) and poplar (Triploid Populus tomentosa Carr) in the presence of phenol with the following weak inorganic acids as catalysts: phosphoric acid (85%), sulfuric acid (36%), hydrochloric acid (37%) and oxalic acid (99.5%). Results show that phosphoric acid (85%) and sulfuric acid (36%) are better than the other catalysts. It was found that lower residue ratios can be obtained under defined reaction conditions: phenol/wood ratio is 4, a 10% catalyst based on the weight of phenol, a temperature of 150°C for 2 h and phosphoric or sulfuric acid. The residue ratios are 3.2% and 4.0%, respectively. __________ Translated from Journal of Beijing Forestry University, 2004, 26(5) [译自: 北京林业大学学报, 2004, 26(5)]     

Preparation and Characterization of Phenolated Wood Using Sulfuric Acid as a Catalyst I: Liquefaction Behavior of Plantation Wood

Chinese fir (Cunninghamia lanceolata) and poplar (Populus spp.) wood meal were phenolated in the presence of sulfuric acid used as a catalyst. The effects of reaction time and reaction temperature on the wood liquefaction were investigated. The results showed that the reaction temperature had the greater influence on the residue content than reaction time. Additionally, the liquefaction curve for the Chinese fir and Poplar were similar in general.     

Factors affecting the resinification of liquefied phenolated wood

Wood of Chinese fir and poplar were liquefied in phenol at 150℃ and atmospheric pressure. The liquefied wood were reacted with formaldehyde to synthesize the liquefied wood-based resin. The factors affecting the resinification and the properties of new resin were investigated. The results show that the formaldehyde/liquefied wood molar ratio, reaction temperature, reaction time and sodium hydroxide/liquefied wood molar ratio have important influence on the resin characteristics. With the increase of formaldehyde/liquefied wood molar ratio, the yield of resin increases, and the flee phenol content of resins decreases, showing that the resinification of liquefied wood is more complete at higher formaldehyde/liquefied wood molar ratios. The reaction temperature on the viscosity of the liquefied resin has considerable effect; the viscosity of resin increased with increasing reaction temperature, and the amount of liquefied poplar resin increased more quickly than that of liquefied Chinese fir resin. The resinification time also has obvious influence on the viscosity of resin; the viscosity of liquefied poplar resin is more sensitive to resinification time compared with that of liquefied Chinese fir. The amount of sodium hydroxide can improve the water miscibility of liquefied wood resin. The optimum sodium hydroxide/liquefied wood molar ratio for preparation of liquefied wood-based resins exceeds 0.4.     

Patterns of variation in chemical compositions of wood from natural populations of Pinus manssoniana Lamb. in Guizhou Province, China

Patterns of variation in the chemical composition of wood,i.e.,holocellulose,cellulose and lignin contents and 1%NaOH extractives were studied in 12 natural populations of Pinus manssoniana Lamb.in Guizhou Province,China,using wood cores as experiment material.The results show statistically significant differences among provenances in holocellulose,cellulose and 1% NaOH extractive contents.The largest coefficient of variation among the provenances was found in the 1%NaOH extractive content and the smallest in the holocellulose content.Variation of lignin content occurred within provenances.Correlations between chemical compositions of wood and factors of local geography and meteorology were largely insignificant.The chemical composition of wood presented patterns of random variation.The correlation of 1%NaOH extractive content with holocellulose content was significant(r=?0.68).There was also significantly negative correlation(r=0.62)between cellulose and lignin content.On the basis of a UPGMA cluster analysis,we identified three provenances of masson pine among the 12 studied,i.e.,those of Wengan,Tongzi and Luodian with high cellulose contents,low levels of 1%NaOH extractive and moderate lignin contents,which we recommend as promising provenances for growing of pulp wood and the manufacture of paper in Guizhou Province     

Analysis on residue formation during wood liquefaction with polyhydric alcohol

Liquefactions of cellulose powder, steamed lignin, alkali lignin, and their mixtures were carried out to analyze the reaction process of wood using polyhydric alcohol. The liquefaction of wood proceeded immediately and wood components were converted to N,N-dimethylformamide (DMF)-soluble components. After that, the condensation reaction occurred with increasing reaction time. However, none of cellulose powder, steamed lignin, and alkali lignin condensed by themselves during their liquefaction. The mixture of cellulose and lignin was also liquefied, and condensed after a long reaction time. The results of analysis showed that the behavior of the mixture resembled that of wood with respect to molecular weight distribution and the main functional groups. Lignin was converted to DMF-soluble compounds in the initial stage of wood liquefaction, followed by cellulose gradually being converted into soluble compounds. After that, condensation reactions took place among some parts of depolymerized and degraded compounds from cellulose and lignin, and were converted into DMF-insoluble compounds. It was concluded that the rate-determining step of wood liquefaction was the depolymerization of cellulose. Furthermore, it was suggested that the condensation reaction was due to the mutual reaction among depolymerized cellulose and degraded aromatic derivatives from lignin or due to the nucleophilic displacement reaction of cellulose by phenoxide ion.Part of this report was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002     

6种木材白腐菌对山杨材木质素分解能力的研究

由于不同的木材腐朽菌的生理特性不同 ,所分泌的酶及酶的活性各不相同 ,因此 ,不同的腐朽菌分解木材的各种成分及相对速度就各不相同 ,而且对于木质纤维基质会有不同的中间代谢产物。本项研究选择了火木层孔菌 (Phelliusigniarius)及另外 5种木材分解能力较强的阔叶树上的白腐菌 :粗毛盖菌 (Funaliagallica)、三色革裥菌 (Lenzitestricolor)、冬拟多孔菌 (Polyporellusbrumalis)、偏肿拟栓菌 (Pseudotrametesgibbosa)和血红密孔菌 (Pyc noporussanguineus) ,研究了它们对山杨木材木质素的分解能力 ,测定了经 6种白腐菌分解一定时期的山杨木材木质素的含量 ,作为木材白腐菌对山杨木材木质素生物降解机制的初步研究 ,旨在为山杨木材生物制浆造纸提供应用基础理论研究 ,同时也可为木质素合理的生物转化为有用的化学品、生物漂白、酶处理防止机械浆的返黄、废水治理、纤维素酶解糖化的微生物前处理等提供相关的借鉴研究 ,以期在生产实践中减轻环境污染并充分利用木质素资源。在无菌的条件下 ,将山杨木片样品分别放入以上 6种白腐菌的平板培养基中受菌侵染 ,一定时间后取出 ,去除木片表面的菌丝体 ,然后分别测定未腐朽材和受菌侵染 4 0d、6 0d、80d和 12 0d时木片样品中木质素的含量 ,分析 6种白腐菌对山杨木     

杉木粉液化与液化产物树脂化的研究

以硫酸为催化剂、苯酚为液化剂采用溶剂热法对杉木粉进行液化,用杉木粉液化产物制备出酚醛树脂;考察了反应温度、反应时间、液比(苯酚-木粉的质量比)和催化剂用量对杉木粉液化效率的影响,并初步探讨了液化产物残渣率对所制酚醛树脂性能的影响。实验结果表明,杉木粉液化的最佳工艺条件是:反应温度160℃,液化时间12 h,液比值3,催化剂用量3%,在此条件下残渣率约为10%。液化产物残渣率的测定表明,升高反应温度、延长反应时间、增加液比和催化剂用量可以降低残渣率,提高液化效率;液比值为0.5~1.5时残渣率随液比增加而显著降低,催化剂用量为0.5%~2%时液化效率的变化明显。红外光谱结果表明,由液化产物所合成的酚醛树脂中羟甲基含量较高。液化产物残渣率低时制备的酚醛树脂残碳率较高。     

Quantifying lignin and holocellulose content in coniferous decayed wood using near-infrared reflectance spectroscopy

To determine the independent decomposition rates of lignin and cellulose of decayed woody debris, a technique for the rapid analysis of lignin and cellulose is required. We applied a near-infrared spectroscopy (NIRS) technique to measure the lignin and holocellulose content in decayed wood. We succeeded in creating partial least-squares (PLS) models to estimate the lignin and holocellulose content in the decayed wood of five species using NIR spectra. Although the accuracy was acceptable for the estimation of a five-species mixed model (R ² = 0.970 for lignin and R ² = 0.962 for holocellulose), it was further improved when the model was applied to each species independently. This combination of NIRS and a PLS model is a valuable tool for the determination of the lignin and holocellulose content in decayed wood. The technique is time efficient (3 min per sample) and non-hazardous (no acid treatment is required).     

马尾松种子园家系木材化学组分的株内纵向变化规律

利用3个22年生马尾松初级种子园自由授粉家系1.3 m、5.3 m和10.0 m 3个高度圆盘,研究3个家系纵向木材化学组分的变化规律。结果表明:综纤维、酸不溶木素、冷水抽提物、热水抽提物、苯醇抽提物、1%NaOH抽提物、灰分和水分等8个化学组分含量指标在树干纵向高度间差异显著。纤维素、综纤维、酸不溶木素、热水抽提物、苯醇抽提物、1%NaOH抽提物、灰分和水分等8个化学组分含量均随着树干高度的增加不断下降。混合取样数据接近整株化学组分的平均水平,因而宜采用混合样分析马尾松化学组分变化。不同家系木材化学组分的纵向均匀性以169号最好,159次之,162最差。     

木材表面非极性化原理的研究 I.木材乙酰化过程中化学官能团的变化

对杉木和“三北”一号杨两种木材的各主要组成进行了酯化处理,研究其在乙酰化过程中木材各主要组成的化学官能团的变化特征和结构的稳定性。结果表明：磨木木质素、纤维素、半纤维素经乙酸酐处理后,红外光谱上的１７４２ｃｍ－１附近均出现了表示酯类ＣＯ伸缩振动的新的吸收峰,表明在乙酰化过程中这些组分的化学结构都有新的非极性酯类化学官能团产生;而极性的羟基官能团的数量均有不同程度的减少;芳香基和脂肪基的结构上均有乙酸酯生成。纤维素酯化程度较低,半纤维素化学结构在乙酰化过程中会发生降解,而木质素和纤维素较为稳定。乙酰化处理是降低木材表面极性的一种有效方法。     

Effect of ozone treatment of wood on its liquefaction

The effects of ozone treatment were investigated to improve the process of liquefaction of wood with polyhydric alcohol solvents. The liquefied wood having a high wood to polyhydric alcohol ratio (W/P ratio) could be prepared by using the wood treated with ozone in the liquid phase. The liquefied wood with a W/P ratio of 2 : 1 had enough fluidity to act as a raw material for chemical products. To get some information about the effects of ozone treatment toward the wood components, cellulose powder and steamed lignin were treated with ozone and liquefied. In particular, ozone treatment in the liquid phase was found to be effective for wood and cellulose powder. On the other hand, steamed lignin self-condensed during liquefaction after treatment with ozone in the liquid phase. Thus, ozone treatment provided lignin with reactive functional groups, and caused the subsequent condensation reaction. Although lignin was converted to a more condensable structure by ozone treatment, the condensation reaction was found to be suppressed for wood during its liquefaction. The wood liquefied products displayed good solubilities in N,N-dimethyl formamide (DMF) even after treatments of long duration. It was suggested that one of the main effects of ozone treatment toward wood was the decomposition of cellulose.Part of this report was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, April 2003     

Changes of chemical properties and the water vapour sorption of <Emphasis Type="Italic">Eucalyptus pellita</Emphasis> wood thermally modified in vacuum

The aim of this study was to evaluate the chemical composition and the dynamic water vapour sorption properties of Eucalyptus pellita wood thermally modified in vacuum. For this purpose, wood samples were thermally modified in a vacuum oven at 160–240 °C for 4 h. Chemical composition were investigated by wet chemical analysis, elemental analysis, as well as Fourier transform infrared (FTIR) analysis, and dynamic water vapour sorption properties were evaluated by dynamic vapour sorption apparatus. The results showed that holocellulose and alpha-cellulose contents decreased and lignin and extractives contents relatively increased during the heat process. Elemental analysis showed a reduction in hydrogen content and an increase in carbon content. FTIR analysis indicated that the degradation of hemicellulose and condensation reactions of lignin occurred. In addition, the thermo-vacuum resulted in a reduction in the equilibrium moisture content of wood during the adsorption or desorption process. And the sorption hysteresis had a decreasing trend with increasing treatment temperature. The development of the hygroscopicity was related to the increase in the relative content of lignin, the degradation of the carbonyl groups in xylan and the loss of carbonyl group linked to the aromatic skeleton in lignin after heat treatment.     

茯苓褐腐过程中木材化学成分的变化

用褐腐真菌茯苓按常规栽培方法对木材进行降解,对比研究了正常材和不同腐朽程度木材化学组成之间的差异,用傅立叶红外光谱仪(FTIR)对样品进行表征.结果发现,腐朽初期,综纤维素和戊聚糖的含量及纤维素结晶度随腐朽时间的延长逐渐降低,木质素和1%NaOH抽出物的相对含量却逐渐升高.当腐朽进行到15周时,综纤维素含量、戊聚糖含量和纤维素结晶度分别由正常材的72.80%、14.95%和40.3%下降到18.57%、8.58%和16.1%,木质素含量和1%NaOH抽出物含量分别从27.30%和12.89%增加到43.88%和70.07%.之后,随着腐朽时间的延长,木材的组成几乎保持不变.FTIR结果证实了相同的变化趋势.     

木粉及其组分的多元醇酸催化热化学液化

分别将木粉、纤维素和木质素在乙二醇中进行热化学液化。研究结果表明木粉中纤维素的非结晶区、木质素和半纤维素首先被液化,而纤维素的结晶区较慢被液化,到液化反应中期基本降解完全,液化产率高于97%。利用在线红外光谱仪跟踪检测了整个液化反应过程,结合GC-MS结果发现:乙二醇在反应过程中脱水生成了二甘醇和三甘醇。在液化反应中,纤维素的糖苷键断裂后生成葡萄糖苷结构,随后葡萄糖苷中的吡喃环也被打开,生成的活性中间体相互反应或与乙二醇反应生成了如3-(2-甲基-[1,3]-二氧戊环-2-基)-丙酸乙酯、乙酰丙酸丁酯等酯类;木质素的苯丙烷结构主要降解为苯酚、2,6-甲氧基苯酚等芳香族衍生物,因此木粉液化产物是聚醚/酯混合多元醇。     

核桃壳胶粘剂化学背景的探讨

探讨漾濞泡核桃壳作木材胶粘剂原料的化学背景。化学分析结果表明:漾濞泡核桃壳中含(硝酸法)纤维素3 3 2 5 %、多戊糖2 6 72 %、木素6 0 94 %、灰分1 1 9%;核磁共振氢谱、紫外和红外光谱的分析结果表明:核桃壳木素以愈疮木基-紫丁香基木素为主,属GS型木素,且G型木素的含量大于S型木素。利用G型阔叶材木素的化学性质可以合成得到与普通酚醛树脂胶合性能相当的核桃壳木素-苯酚-甲醛共聚树脂。     

云南甜竹化学成分分析

对云南甜竹的9项化学组成进行分析,结果表明：云南甜竹的综纤维素、木素等细胞壁主要物质含量和一般木材接近,灰分和各种抽出物含量介于木材和草类原料之间 除综纤维素和灰分在秆高方向上表现出明显的递增分布规律外,云南甜竹其它各化学成分在秆高方向上未呈现出明显的分布规律。从化学组成角度分析认为,云南甜竹满足制浆造纸工业对原材料的要求,可以作为发展竹浆产业的原料竹种,值得在气候适宜的地区推广种植。