芦苇造纸黑液中木质素的提取及其结构分析

采用有机溶剂和无机溶剂结合的方法,提取纯净的木质素.首先通过酸析的方法,从芦苇造纸废液中提取粗的木质素,研究了pH值为2.0,反应温度为60℃,絮凝时间为45min,絮凝温度为70℃是提取木质素的最佳条件.然后用乙醇对粗木素进行纯化,分离提取纯木质素,由红外光谱(FTIR)、紫外-可见光谱(UV-Vis)、核磁共振(1 H NMR)、元素分析、以及热重TG分析技术对纯木质素进行了分析,可知芦苇造纸废液中的木质素主要是由紫丁香基团和愈创木基团组成.通过分析其结构,对其进行改性,合成应用于油田驱油方面的表面活性剂。     

造纸污泥中提取的木质素改性研究

为提高以造纸污泥为原料制备的木质素减水剂的减水性,用H2O2 和Na2SO3分别对木质素进行氧化、磺化.氧化工艺条件为:对10g木质素,过氧化氢用量为1.5g,反应温度80℃,pH=9,反应时间2 h.所得到的产品比一般磺化产品的减水性能优越,经检测各项主要指标达到普通减水剂的国家标准(GB8076-1997).     

草浆造纸黑液中胶体成分的测定方法及其对黑液碱回收的影响

根据草浆造纸黑液组成的特殊性，研究了草浆黑液中液体成分的测定方法，进行了样品分析和回收率试验．取得了较满意的结果。在些基础上讨论了草浆黑液中胶体成分对于黑液碱回收过程的影响。     

木质素类吸附剂的研究进展

木质素是植物的主要成分之一,由苯基丙烷单元随机聚合而成,在木质素结构中有很多活性功能基团.取代的苯基丙烷单元聚合后与纤维素和半纤维素-起构成植物的主要骨架.本文对近年来木质素类吸附剂,主要是基于木质素的活性炭和离子交换树脂的制备和应用做一综述,并对木质素类吸附剂的今后的研究发展做了简要的分析.     

复合型改性木质素基钻井液用降粘剂的性能研究

以马尾松硫酸盐制浆黑液为原料,经化学改性制备复合型改性木质素基钻井液用降粘剂,并对其在钻井液中的降粘性能进行实验室评价。研究结果表明,该降粘剂既能发挥无机降粘剂良好的降粘作用,又具有木质素系降粘剂良好的抗温、抗盐效果,具有较好的协同作用。加入0.5%降粘剂的淡水基浆,降粘率可达96.7%。     

木质素结构及分析方法的研究进展

木质素广泛存在于高等植物中,是仅次于纤维素的地球上第二丰富的生物聚合体,有效地利用自然界中含量丰富的木质素具有重大的意义。然而,由于木质素结构的复杂性,对其具体结构的认识和寻找合适的木质素结构分析方法成为人们长期探索的课题。本文主要阐述了目前对木质素单体的生物合成途径和木质素的化学组成、官能团、单体间的连接方式、木质素模型化合物等木质素结构方面的研究进展,并从降解法和非降解法两个角度介绍了常用的木质素结构分析方法。     

竹浆黑液高效减水剂的结构表征及吸附研究

研究了竹浆黑液混凝土高效减水剂(GCL1-JB)的结构和吸附特征.将GCL1-JB先通过超滤和离子交换树脂提纯,再通过凝胶柱层析分级,然后选择4种窄分子量分布的GCL1-JB级分进行结构表征和吸附研究.结果表明,GCL1-JB具有高分子量和高磺化度的结构特征.不同分子量级分的GCL1-JB的化学分子结构相似,但其中磺酸基含量随着分子量增大而减少,而芳香环含量随着分子量增大而增大.GCL1-JB在阳离子表面能形成平整的自组装吸附膜,其中高分子量级分的GCL1-JB因磺酸基含量较低,分子较卷曲,故吸附量较大.     

萝卜木质素的提取及其抗自由基活性

以浓度为80%的乙二醇水溶液为溶剂,采用高沸醇溶剂法(HBS)从萝卜中提取萝卜木质素,采用红外光谱、紫外光谱和~1H NMR等方法对其结构进行了表征.结果表明,所提取的萝卜木质素具有木质素类化合物的典型结构特征.采用可见光分光光度法研究了萝卜木质素对DPPH·自由基和HO·自由基的抑制效率.结果表明萝卜木质素对两种自由基均具有较高的抑制率,其对两种自由基的抑制率最高分别为90%和68.3%.     

木质素脱甲基化改性及产物结构表征

通过对不同催化剂、催化剂量、反应温度和反应时间等反应条件下得到的改性木质素与甲醛反应活性的研究,确定了木质素脱甲基化反应条件,并通过FT-IR半定量、GPC1、H NMR对木质素脱甲基化前后结构进行表征。FT-IR半定量表明木质素甲氧基由反应前的0.990降至0.765,酚羟基由1.174增至1.529;GPC表明木质素脱甲基化后大分子木质素发生了降解,分子量小于2000的木质素含量由由改性前的38%增至改性后的51%;1H NMR表明木质素改性后脂肪族侧链与苯环分离,同时大量-βO-4醚键裂解。     

水葫芦木质素的提取及其苯胺吸附性能

采用碱提法从生态入侵植物水葫芦中提取木质素,利用傅立叶红外光谱(FT-IR)和扫描电镜(SEM)等手段对所获得的木质素进行表征,研究了水葫芦木质素对水中苯胺的吸附性能,考察了溶液p H值、吸附时间、初始浓度等因素对水葫芦木质素吸附苯胺的影响。当Na OH溶液浓度0.1 mol/L,提取时间4 h,温度100℃,料液比1∶20时,水葫芦木质素的收率最大为6.81%。红外图谱显示,在1 456~1 656 cm-1处存在木质素的芳香环骨架振动吸收峰;扫描电镜显示,木质素呈大量细小的颗粒,木质素颗粒表面存在许多微小的孔状结构,有利于吸附作用的发生。在室温下,溶液p H 6.0,苯胺初始浓度为150 mg/L,吸附剂用量为5 mg,吸附时间120 min时,水葫芦木质素对苯胺的最大吸附容量为12.2 mg/g。苯胺吸附实验数据拟合符合准二级动力学模型以及Langmuir吸附等温模型。水葫芦木质素对苯胺的吸附以单分子层化学吸附为主,属于优惠吸附。相同吸附条件下,水葫芦木质素对湖泊水样中苯胺的吸附与实验模拟水样的吸附效果相近。水葫芦木质素可作为富集分离材料用于分析样品制备以及水中污染物的吸附。     

Valorization of Rice Straw via Hydrotropic Lignin Extraction and Its Characterization

Rice straw hydrotropic lignin was extracted from p-Toluene sulfonic acid (p-TsOH) fractionation with a different combined delignification factor (CDF). Hydrotropic lignin characterization was systematically investigated, and alkaline lignin was also studied for the contrast. Results showed that the hydrotropic rice straw lignin particle was in nanometer scopes. Compared with alkaline lignin, the hydrotropic lignin had greater molecular weight. NMR analysis showed that β-aryl ether linkage was well preserved at low severities, and the unsaturation in the side chain of hydrotropic lignin was high. H units and G units were preferentially degraded and subsequently condensed at high severity. High severity also resulted in the cleavage of part β-aryl ether linkage. ³¹P-NMR showed the decrease in aliphatic hydroxyl groups and the increasing carboxyl group content at high severity. The maximum weight loss temperature of the hydrotropic lignin was in the range of 330–350 °C, higher than the alkaline lignin, and the glass conversion temperature (T_g) of the hydrotropic lignin was in the range of 107–125 °C, lower than that of the alkaline lignin. The hydrotropic lignin has high β-aryl ether linkage content, high activity, nanoscale particle size, and low T_g, which is beneficial for its further valorization.     

麦草碱木素及其热化学降解产物相对分子质量分布的测定

以pH=10的0．1mol/L NaNO3溶液为流动相，在Ultrahydrogel柱上测定麦草碱木素及其热化学降解产物的相对分子质量分布，测定碱木素降解产物所用洗脱液宜用pH10的0．1mol/LNaNO3水溶液，比较了由于样品结构特性和物理性质差异而造成的流动行为的差异，并确定两种样品各自的色谱条件。     

高沸醇溶剂法提取胡萝卜木质素

以乙二醇水溶液为溶剂,采用高沸醇溶剂法（high boiling solvent,HBS）从胡萝卜中提取木质素。 结果表明,将胡萝卜干粉投入到质量分数为80%的乙二醇中,在210 ℃、料液质量比为1∶6的条件下蒸煮2 h,木质素收率最高（17.79%）。 采用红外光谱（FTIR）、紫外光谱(UV)和核磁共振(1H NMR)等测试技术对其结构进行了表征。 结果表明,高沸醇法提取的胡萝卜木质素具有木质素类化合物的典型结构特征。 通过元素分析和甲氧基含量的测定,得到胡萝卜木质素的C9结构模型为C9H9.62O1.99(OCH3)0.96。 利用Fenton反应产生羟基自由基·OH,研究了胡萝卜木质素对羟基自由基的抑制效率。 结果表明,胡萝卜木质素在较低的浓度（50 mg/L）下对羟基自由基就具有较强的抑制效果,抑制率最高可达64.9%。     

Capillary - Pore Structure of Hydrolyzed Lignin Derivatives

The polymolecular nature of sorption by various samples of hydrolyzed lignin is studied by water-vapor sorption     

Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives

To investigate the effects of lignin methylolation and lignin adding stage on the resulted lignin-based phenolic adhesives, Alcell lignin activated with NaOH (AL) or methylolation (ML) was integrated into the phenolic adhesives system by replacing phenol at various adhesive synthesis stages or directly co-polymerizing with phenolic adhesives. Lignin integration into phenolic adhesives greatly increased the viscosity of the resultant adhesives, regardless of lignin methylolation or adding stage. ML introduction at the second stage of adhesive synthesis led to much bigger viscosity than ML or AL introduction into phenolic adhesives at any other stages. Lignin methylolation and lignin adding stage did not affect the thermal stability of lignin based phenolic adhesives, even though lignin-based adhesives were less thermally stable than NPF. Typical three-stage degradation characteristics were also observed on all the lignin-based phenolic adhesives. Three-ply plywoods can be successfully laminated with lignin based adhesives, and it was interesting that after 3 h of cooking in boiling water, the plywoods specimens bonded with lignin-based phenolic adhesives displayed higher bonding strength than the corresponding dry strength obtained after direct conditioning at 20 °C and 65% RH. Compared with NPF, lignin introduction significantly reduced the bonding strength of lignin based phenolic adhesives when applied for plywood lamination. However, no significant variation of bonding strength was detected among the lignin based phenolic adhesives, regardless of lignin methylolation or adding stages.     

丹参木质素及其单体含量的测定

本文建立了一种准确、快速的检测丹参中木质素及其单体含量的方法.采用Klason法和紫外分光光度法分别对丹参根和茎中酸不溶性木质素(Klason木质素)和酸溶性木质素含量进行了测定;运用硫代酸解法并结合气相色谱-质谱法(GC-MS)分别对丹参根和茎中各木质素单体组成进行了分析.结果显示,总木质素在丹参根和茎中的含量分别为...     

Recovery of Vanillin and Syringaldehyde from Lignin Oxidation: A Review of Separation and Purification Processes

Lignin is an underexploited side-stream of pulp and paper industry and biorefineries, being used for energy production at mill site or as low value material for dispersants or binding applications. However, an integrated process of reaction and separation can be implemented for the production of high added-value monomeric phenolic chemicals such as vanillin and syringaldehyde. In this review, the main research advances in the recovery of vanillin and syringaldehyde resulting from oxidation of lignin are addressed, covering various separation methodologies namely liquid-liquid extraction, supercritical fluid extraction, distillation, crystallization, membrane separation, and adsorption. Studies in this area started in the early years of the 20^th century, but in the last decades several processes have been suggested, mainly for vanillin separation. Finding the ultimate industrially feasible process is still a necessary task and this review points out the most promising technologies and sequence of processes.