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1.
杉木粉液化与液化产物树脂化的研究 总被引：2，自引：0，他引：2
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。 相似文献
2.
研究了硫酸催化条件下，将恩茅松在苯酚中液化用于制备酚醛树脂的技术工艺，分析了各工艺参数对思茅松液化效率的影响，测定了由液化产物制备的液化木基酚醛树脂的物理化学性质和胶合强度。结论如下：1）．液比、反应温度、时间和木粉目数是影响液化反应效率的重要因素，液化产物的残渣率均随上述工艺参数值的升高而降低。2）．残渣含量对树脂物化性质和胶合强度均有影响，残渣含量降低，树脂粘度减小，聚合时间缩短，游离酚含量降低，胶合强度升高。3）．甲醛／苯酚摩尔比对树脂的物化性质和胶合强度也有影响，甲醛／苯酚摩尔比增加，树脂粘度增加，聚合时间减少，游离酚含量减低，胶合强度升高。 相似文献
3.
IKEDA Atsushi 《中国林业科技(英文版)》2003,(2)
By means of gel permeation chromatography analysis, the molecular weight of liquefied wood under different reaction conditions was investigated to trace the change in the structural characteristics of the liquefied wood. The insoluble residues were analyzed by Fourier transform infrared to investigate the liquefaction order of three main wood components. The results indicate that both reaction temperature and reaction time could affect the molecular characteristics of the liquefied wood obtained. The molecular weight of liquefied Chinese Fir wood is higher than that of liquefied Poplar wood under most of reaction conditions. During wood liquefaction, lignin is liquefied firstly. Hemicellulose is liquefied in the middle stage and cellulose is the most difficult to be liquefied. 相似文献
4.
Masahiko Kobayashi Toshiyuki Asano Mikio Kajiyama Bunichiro Tomita 《Journal of Wood Science》2005,51(4):348-356
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 相似文献
5.
Zhang Qiu-hui Zhao Guang-jie Hu Shi-yu 《中国林学(英文版)》2005,7(2):38-42
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. 相似文献
6.
7.
Effects of phosphoric acid on liquefaction of wood in phenol and optimum liquefaction processing parameters 总被引：6，自引：0，他引：6
ZhangQiuhui ZhaoGuangjie JieShujun 《中国林学(英文版)》2004,6(3):50-54
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%. 相似文献
8.
为了综合利用油茶饼粕,分析了油茶饼粕的基本组成,采用苯酚为液化剂,硫酸为催化剂,对油茶饼粕进行了液化实验。结果显示油茶饼粕中糖类、粗纤维和粗蛋白质的总质量分数约为75%,能够有效进行液化。研究了反应温度、苯酚与油茶饼粕的质量比(液比)、催化剂的用量及液化时间对液化反应的影响,实验得出较佳的液化工艺条件为:硫酸用量4%,液化时间1.5 h,液化温度140℃,液比值4,此时液化残渣率16.25%。利用傅里叶红外光谱(FT-IR)分析了油茶饼粕及其液化残渣和产物的结构特征,结果显示苯酚与油茶饼粕组分发生了明显酚化反应和醚化反应,形成了更多的活性官能团。油茶饼粕中蛋白质结构遭到破坏,蛋白质也发生了液化反应。 相似文献
9.
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 相似文献
10.
超临界甲醇液化杉木工艺的探讨 总被引：1，自引：0，他引：1
采用超临界流体技术液化杉木，考察了溶木比、温度、压力及时间对液化率及分子特征的影响，并使用FTIR和XRD对液化产物及其残渣进行了分析。结果表明，当溶木比为12：1，温度为270℃，压力为12MPa，时间为60min时，有较高的液化率，且液化产物的分子量分布均匀。FTIR和XRD的分析结果显示，杉木超临界液化产物中含有大量的具有反应活性的芳核衍生物，同时也仍然有一些微晶结构存在。 相似文献
11.
Liquefaction of beech wood in various supercritical alcohols 总被引：1，自引：0，他引：1
The liquefaction of Japanese beech (Fagus crenata Blume) was studied with various straight-chain alcohols in subcritical and supercritical states using a batch-type reaction
vessel to obtain liquid fuel from lignocellulosics. Under the reaction condition of 270°C, beech wood was liquefied to some
extent in all alcohols with about 50%–65% insoluble residue left after treatment for 30min. Under the condition of 350°C,
however, more than 90% of wood was decomposed and liquefied in all alcohols. Alcohols with longer alkyl chains liquefied lignocellulosics
in shorter reaction times. Because many kinds of alcohols, such as methanol and ethanol, can be produced from biomass, 100%
biomass-based liquid fuel can be prepared by supercritical alcohol technology when using such bioalcohols.
This study was presented in part at the 55th Annual Meeting of the Japan Wood Research Society, Kyoto, Japan, March 16–18,
2005 相似文献
12.
杉木液化产物制备环保型PF树脂的研究 总被引：1，自引：1，他引：0
用硫酸和苯酚将杉木液化,采用傅立叶变换红外光谱和凝胶渗透色谱技术对液化产物进行了分析,并对用液化产物代替苯酚制备PF树脂的工艺进行了探讨。研究结果表明:杉木液化产物中含有大量的具有苯环结构的小分子活性物质,分子量主要分布在800～2 300之2;原料配比、树脂化温度、升温方式和残渣率等因素对PF树脂的质量有明显影响,采用优化工艺制备的PF树脂的游离酚和游离醛的含量分别为0.5%和0.3%,且胶合性能优良。 相似文献
13.
Hisashi Miyafuji Kenji Miyata Shiro Saka Fumio Ueda Midori Mori 《Journal of Wood Science》2009,55(3):215-219
Reaction of Japanese beech (Fagus crenata) in an ionic liquid, 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), which can dissolve cellulose, was investigated.
Although both lignin and polysaccharides such as cellulose and hemicelluloses can be liquefied at a treatment temperature
of around 100°C, the liquefaction of polysaccharides mainly occurs at the beginning of the treatment with [C2mim][Cl]. Cellulose
crystallinity in the wood was gradually broken down as the treatment continued. The solubilized polymers were depolymerized
to low molecular weight compounds. The results indicate that [C2mim][Cl] is an effective solvent and reagent for the liquefaction
of wood components and subsequent depolymerization of them.
Part of this report was presented at the 58th Annual Meeting of the Japan Wood Research Society, Tsukuba, April 2008 相似文献
14.
采用硫酸催化剂,考察了苯酚与核桃壳质量比等条件对核桃壳液化的影响。结果表明相同液化条件下,随着苯酚与核桃壳质量比从2∶1升至5∶1,残渣率从26.49%降至6.60%;随着浓硫酸加入量从2%增至4%、反应时间从5 min延至120 min、反应温度从100℃增至150℃,残渣率则分别从20.79%降至10.48%、48.84%降至15.62%、28.86%降至9.39%,游离酚含量分别从17.32%降至12.67%、41.71%降至10.25%、21.94%降至14.33%。同时,液化产物重均相对分子质量(MW)可降至706~1 030、分散度可降至1.04~1.25;液化产物中高相对分子质量部分随着苯酚与核桃壳质量比的增加有所降低,但随着浓硫酸加入量、液化反应时间和温度的增加而有所增加;核桃壳液化产物/苯酚/甲醛共缩聚树脂胶黏剂(WPF)与传统酚醛树脂胶黏剂(PF)的对比表明,WPF的胶接强度可达1.33 MPa,可作为胶合板用胶黏剂。 相似文献
15.
16.
木材苯酚液化产物制备碳纤维的初步探讨 总被引：2，自引：0，他引：2
为拓宽木材液化产物的应用领域,提高木材产品的附加值,实现木材的高效利用,在研究木材苯酚液化产物特性的基础上,提出了木材苯酚液化产物碳纤维材料的制备构思和工艺路线。利用木材苯酚液化产物为前驱体,通过加入反应剂如六次甲基四胺等调制纺丝液,熔融纺丝后将纤丝在甲醛和盐酸混合溶液中加热固化形成网状交联结构,然后在惰性气体保护下高温炭化制备成碳纤维,同时对制备过程中可能存在的影响因素进行了分析。 相似文献
17.
木材的液化及其在高分子材料中的应用 总被引：28，自引：3，他引：28
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，进一步可制备新型高分子材料如胶粘剂、注模塑料、泡沫塑料、纤维材料等，具有广泛的应用前景，是木材化学和木材利用技术新开辟的研究领域。本文综述了近二十年来木材液化技术的发展状况，内容涉及木材液化方法，液化反应机理，液化产物的开发利用。 相似文献
18.
Zhang Chen-xia Huang Jin-tian 《中国林学(英文版)》2006,8(3):38-42
1 Introduction Desert shrubs are made up of natural composite mate- rials, composed of cellulose, hemicellulose and lignin. Although there are a large number of hydroxyl groups in them, these are not fully used due to the high crys- tallinity of cellulose and tight interconnection among polymeric components in wood (Cheng et al., 2002). Liquefaction of wood is a new technique in wood in- dustries. It is a novel process which effectively con- verts the chemical composition of wood into macro- … 相似文献
19.
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)] 相似文献
20.
Preparation and characterization of the phenolated wood using hydrochloric acid (HCl) as a catalyst 总被引：7，自引：0，他引：7
Summary Birch (Betula maximowicziana Regel) wood meal was liquefied in the presence of phenol using hydrochloric acid (HCl) as a catalyst at a temperature of
150 °C for 2 h in an autoclave. It was found out that HCl acid could be used as an effective catalyst for the hydroxy phenylation
of wood under the experimental conditions. In this study the effect of the concentration of the acid catalyst and the phenol-to-wood
ratio on the liquefaction were investigated. The results showed that the phenol-to-wood ratio and the concentration should
be increased to a certain degree in order to achieve a less residual rate and sufficient amount of combined phenol. The phenolated
woods had apparent flow temperatures in the range of 134.4 to 199.8 °C, being higher than that of a commercial novolak resin.
Furthermore, increases in the HCl concentration during liquefaction reaction led to increase in the apparent flow temperature
of the resulting phenolated woods. However, the changes in the liquid ratio did not bring about evident changes. The relationship
between shear stress (τ) and shear rate
showed that the phenolated wood resin melts were shear thinning fluids. The dependences of the apparent melt-viscosities
(η) of the phenolated woods and a commercial novolak resin on the shear rates (
) have the similar tendencies, however, it was found the viscosities of the phenolated woods are about one order higher than
that of commercial novolak resin. 相似文献