竹材酚醇液化及其应用研究进展

竹材酚醇液化是竹材综合利用的有效方法之一,通过溶剂反应破坏竹材纤维素的结晶结构、半纤维素和木质素高分子结构,使其分子链断裂,降解成带有反应活性的羟基化合物,可以用于制作胶黏剂、发泡材料和碳纤维等。文章分析了竹材液化原理、酚醇液化技术,以及竹材酚醇液化产物的应用研究现状,认为该领域今后需要加强基础理论和预处理技术的研究,尽快制定相关产品标准,实现竹材资源的高利用率和高附加值。     

竹材液化制备墙体新材料的研究进展

分析我国竹材加工利用现状,介绍浙江省林业科学研究院与南京林业大学合作研发的"小径竹液化发泡制备轻质高强度墙体工程材料技术"的背景及主要技术内容。该技术利用小径竹及竹材加工剩余物,在催化液化及液化产物树脂化、液化树脂制备发泡材料,及液化树脂与其他材料复合等方面,具有突破性技术。     

竹材苯酚液化物及其甲醛树脂的FT-IR分析

采用傅立叶红外光谱和核磁共振法分析了竹粉在苯酚溶剂作用下酸催化液化产物的化学结构,以及液化物-甲醛树脂胶黏剂的结构特征.分析表明:竹材苯酚液化物的FT-IR图谱在1595.32～1512.70 cm-1处C=O伸缩振动、C=C伸缩振动、芳环骨架振动增强,在 1360.77 cm-1 处面内O-H弯曲振动、1028.62 cm-1 伯醇C-O伸缩振动及手纹区有强吸收峰;1512.70 cm-1处酚类C-O吸收及832.79～691.68 cm-1 处吸收带增强.竹材苯酚液化物-甲醛树脂和普通酚醛树脂的FT-IR图谱非常类似.     

竹材残料液化及其液化物胶粘剂的制备

研究竹材残料在苯酚介质中液化处理所需的条件及其效果,探讨了酚竹比、催化剂种类及用量、液化温度及液化时间等因素的影响;并用竹材液化液合成高分子胶粘剂。结果表明,竹粉在酚竹比(3:1～1:1),用HC1或BF_3作催化剂,液化温度115℃条件下,处理2h完全液化,用竹材液化物合成胶合剂,其反复沸水煮后平均胶合强度大于1.0MPa,IR光谱表明液化物酚醛(BLF)胶与酚醛胶结构基本一致。     

生物质溶剂液化研究进展

本文阐述了生物质液化溶剂的种类和特性、原料适应性、液化作用原理和液化产物等,总结了国内外在液化溶剂选择、应用等方面的研究情况,探讨了生物质溶剂液化发展趋势,旨在为生物质能的高效利用提供参考.     

竹材苯酚液化及胶黏剂制备工艺

采用单因素试验和正交试验研究了竹材加工剩余物的苯酚液化工艺,并进一步研究了竹材苯酚液化产物-甲醛树脂胶黏剂(BPF)的制备工艺和性能。试验结果表明:竹材苯酚液化过程中,液化温度对液化效果的影响最为显著,其次是液比和液化反应时间,催化剂用量2%~4%范围内对液化效果影响不大。竹材加工剩余物苯酚液化的优选工艺为:液固比值3.5、催化剂用量4%、液化温度145℃、液化时间60 min;在此工艺下竹材液化率为99.1%。胶黏剂制备过程中,竹材苯酚液化物与甲醛溶液(甲醛质量分数为37%)的合理质量比为100∶164.8~199.5,其中以100∶182.1较佳。BPF的固化温度低于普通酚醛树脂胶黏剂(PF),因而可在较低温度下固化良好,在130℃或140℃热压温度条件下,用其制备的胶合板的胶合强度均比较理想,热压温度为140℃时的试验结果更佳。     

竹材液化及竹材液化树脂胶性能研究

研究竹材在苯酚液中酚竹比、催化剂、液化温度等因素对液化的影响，当用HCl或BF3作催化剂、添加量5％、酚竹质量比2—1：1时，115℃下达到竹材完全液化。液化竹材(BL)与甲醛反应，当液化物中苯酚与甲醛摩尔比1：1．6—2．0条件下，制得室外级液化竹材酚醛树脂胶(BLF)。通过TG—DSC分析固化行为表明，BLF比酚醛树脂胶(PF)有更低的固化温度；BLF与PF出现基本一致的IR特征峰。     

竹材加工剩余物液化及液化产物制备发泡树脂的工艺研究

采用苯酚和聚乙二醇-400复合液化试剂,对竹材加工剩余物进行液化和液化产物的树脂化试验。采用单因素法,探讨主要工艺因素对液化效果及对树脂性能的影响,得到竹材酚醇复合液化工艺及树脂化工艺的优化参数。利用液化产物制备的树脂,可用于制造建筑用发泡材料,提高竹材加工剩余物的附加值。     

Cu-Ni掺杂多孔金属氧化物催化竹材的液化

【目的】探究超临界甲醇介质中反应因素对Cu、Ni掺杂多孔金属氧化物(PMO)催化竹材液化产物的影响,以揭示活性组分在竹材液化过程的作用。【方法】以类水滑石为前驱体,通过共沉淀方法制备Cu、Ni掺杂的PMO催化剂,采用XRD、BET、SEM对催化剂进行表征。竹材液化在超临界甲醇介质中进行,液化产物采用GC-MS分析。通过单因素分析Cu/Ni比、催化剂用量、反应温度和反应时间对产物组成和分布的影响。【结果】XRD显示,Cu、Ni掺杂的镁铝水滑石结晶状况良好,呈现水滑石特有的7个衍射峰,未出现Cu O、Ni O的衍射峰。Cu、Ni的掺杂浓度越高,比表面积越小。SEM分析显示,类水滑石前驱体呈典型层状结构,经过焙烧后,层状结构消失,氧化物粒子发生团聚。随着Cu/Ni比增加,酮类产物收率呈逐渐增加趋势;在Cu/Ni比为1∶1时,醇类和烃类产物含量最多,而酚类和酯类含量最少。随着催化剂用量增加,酮类、醇类和烃类收率逐渐增加,特别是在用量20%时上升趋势尤为明显。反应温度高于甲醇的超临界温度时,酮类、醇类和烃类等含氧量相对较低的产物呈大幅度上升,而酯类和其他产物(主要包括醚类、酸类、呋喃类等)显著下降。【结论】Cu O和Ni O在复合氧化物中高度分散,掺杂的PMO具有更小的比表面积。甲醇的超临界温度是影响液化产物组成和分布的关键因素。随着竹材液化反应深入进行,不饱和官能团在甲醇裂解提供的原位供氢体系中发生加氢还原反应,生成含氧量相对较低的醇类、酮类和烃类产物。Ni的添加能够提高催化剂活性组分Cu的分散度,改善催化剂结构并提高其稳定性,从而提高催化剂对竹材液化的催化活性,同时Ni的加入和含量的增加可使混合氧化物的酸、碱性得到调变,改变PMO催化剂的催化活性,促进产物定向分布。     

[Psmim]HSO_4离子液体催化液化木材及其产物表征

合成了1-磺酸丙基-3-甲基咪唑硫酸氢盐离子液体([Psmim]HSO4),对其结构进行了傅里叶红外光谱(FT-IR)和核磁共振(13C NMR)表征。以正辛醇为溶剂,初步考察了该离子液体对杉木屑液化的催化性能,并对残渣、重油和轻油液化产物进行了FT-IR、X射线粉末衍射(XRD)、热重分析(TG)、气质联用(GC-MS)表征。FT-IR和13C NMR分析结果证实了合成产物与目标离子液体结构一致。液化实验结果表明该离子液体具有较好的催化液化性能,10 g杉木屑、60 g正辛醇在催化剂用量8.6 mmol、150℃、60 min条件下,木屑的液化率达66.5%。液化残渣表面的木质素衍生物含量高;轻油主要由纤维素和半纤维素的液化产物组成,重油主要由木质素的液化产物组成。     

竹材液化树脂发泡材料发泡工艺的研究

利用竹材液化产物树脂发泡,制备新型墙体材料。在已进行竹化液化和树脂化优化工艺试验的基础上,通过单因素试验,筛选出发泡剂为正戊烷;再通过正交试验,分析发泡剂、填料和固化剂等用量,对发泡材料表观密度和压缩强度的影响。在试验得出优化工艺的条件下,制得发泡材料的表观密度约0.14g/cm3,压缩强度达454.5kPa。     

Research into hydro-liquefaction of bamboo based on GPC

We investigated hydrogenated catalytic liquefaction of bamboo. By comparing the effect of three kinds of conditions on liquefaction, i.e. liquefaction under vapor pressure, liquefaction under high hydrogen pressure and liquefaction under high hydrogen pressure with alkaline as a catalyst, we obtained the conditions for optimum results. The reaction temperature was 170°C, the initial hydrogen pressure 4.0 MPa, the reaction time 80 min, with sodium hydroxide as the catalyst, with a weight amounting to 8.05% o...     

在酸催化下不同形态木材液化的研究

对粉状、纤维状和刨花状等形态木材,在不同酸催化下的液化效果进行的研究发现,木材液化率几乎不受木材颗粒粒度的影响,木液比和催化剂的种类是影响液化反应的重要因素,对液化率的影响较大.     

竹粉乙醇-苯酚加压液化工艺研究及产物表征

以乙醇-苯酚为液化剂,浓硫酸为催化剂,采用高温高压(3.8 MPa)的方法对竹粉进行了液化处理。通过响应面分析法确定最佳液化工艺条件为:在苯酚和竹粉质量比(酚固比)为1∶1、乙醇和竹粉质量比(醇固比)为18∶1,浓硫酸用量(以竹粉质量计)5%,反应温度200℃,反应时间70 min时,液化率达98.5%。液化残渣的红外光谱(FT-IR)、扫描电镜(SEM)和热重分析(TG)结果证实了竹粉中化学组分的分子结构发生了明显的变化,复合溶剂液化使芳环上有不同取代基的化合物形成,液化残渣主要由木质素及其衍生物构成;竹粉液体产物(生物质油)的GC-MS分析结果表明,生物质油的成分比较复杂,主要包括酯、酚和酮等化合物,平台化合物乙酰丙酸乙酯GC含量为10.11%。     

Technologies of liquefaction of bamboo and preparation of adhesive

The technology of liquefying processed-waste bamboo with phenol is investigated by single factor trials and an orthogonal design. We studied the preparation technology and properties of adhesives from this phenol-liquefied bamboo with formaldehyde (BPF). The results show that temperature has a significant effect on liquefaction. The effect of the mass ratio of phenol to bamboo comes second and the catalyst dosage within the range of 2%–4% is the least effective. The optimum conditions of liquefaction are as follows: a mass ratio of phenol to bamboo 3.5, a catalyst dosage of 4%, liquefying temperature 145°C and liquefying time 60 min. The liquefaction rate of bamboo reached 99.1%. For the preparation of the adhesive, a mass ratio of liquefied bamboo products to formaldehyde (37%) is 100 to 164.8–199.5, while the ratio 100 to 108.2 is the best. This adhesive has a lower curing temperature than that of normal PF resin. At a hot-press temperature of 130 or 140°C, this new adhesive provides excellent bonding strength of plywood. The most favorable temperature for hot-pressing is 140°C. __________ Translated from Chemistry and Industry of Forest Products, 2007, 27(6): 65–70 [译自: 林产化学与工业]     

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     

Rapid wood liquefaction by supercritical phenol

Wood was rapidly liquefied at the supercritical temperature of phenol. Under these conditions, wood was liquefied by over 90% for 0.5 min, and the combined phenol content of the obtained liquefied wood reached about 75%. The effects of various reaction conditions on liquefaction were investigated. With increases in reaction temperature, phenol/wood weight ratio, and the charged mass-to-reactor capacity (w/v) ratio, the amount of methanol-insoluble residue decreased and combined phenol content increased. The range of molecular weights and polydispersity of the products obtained after the time at which sufficient liquefaction was achieved were from 400 to 600 and from 1.5 to 2.5, respectively. Wood showed a marked decomposition to low molecular weight components early in the reaction, and then the molecular weight increased slightly with increasing reaction time. The properties of liquefied wood were investigated and compared with those obtained with conventional liquefaction methods. Combined phenol content was similar to that obtained by other liquefaction methods, except the sulfuric acid–catalyzed method, which resulted in flow properties comparable to those of other liquefaction methods. The flexural strength of moldings prepared using liquefied wood was also comparable to those prepared by other liquefaction methods.