基于木素填料的脲醛树脂胶粘剂研究

研究了面粉、碱木素和木素磺酸钙对脲醛树脂(UF)胶粘剂性能的影响,探讨了碱木素、木素磺酸钙用作胶粘剂填料的可行性。研究结果表明:UF胶粘剂的固含量随着填料用量的增加而增大;UF胶粘剂的固化时间和pH值随面粉或木素磺酸钙用量的增加而降低,却随碱木素用量的增加而增大;使用含木素填料的UF胶粘剂压制胶合板,当w(木素)=15%～20%、施胶量为240～260g/m2时,胶合板的湿态胶合强度略高于纯UF胶粘剂压制的胶合板;以m(面粉)∶m(木素)=1∶1作为混合填料,其干态胶合强度远高于国家标准,并且均高于1.05MPa,其湿态胶合强度能达到国际标准。     

碱木素性能及应用研究进展

碱木素是一种来源丰富、价格低廉的可再生资源。综述了碱木素在表面活性剂、高分子材料、农用化学品等领域的应用研究最新进展 ,分析了提高其性能的改性方法 ,认为对碱木素的研究不仅可以减少纸厂制浆黑液对环境的污染 ,而且能高值利用碱木素 ,具有很好的社会和经济效益。     

杨木胶合板专用UF树脂胶的研究

速生杨木用于生产胶合板是近年内开始的，为解决杨木胶合板的胶合强度较低，油漆后发生鼓泡等质量问题，本文从木材的ｐＨ值、缓冲容量等方面着手，研究杨木的特性，并研制了适合杨木胶合板生产的专用ＵＦ树脂胶。     

网球拍用木质素胶粘剂的制备与性能研究

为了制备出适宜于网球拍用木质素胶粘剂,采用黏度计、拉伸试验机等手段,考察了碱浓度、酚醛比、反应时间和木质素添加量对网球拍用木质素胶粘剂性能的影响.结果 表明,随着碱浓度增加,胶粘剂黏度、固含量逐渐增大,在碱浓度为8％时取得胶合板胶合强度最大值,且胶合板未出现透胶现象;随着酚醛比或反应时间延长,胶合板的胶合强度逐渐增加且...     

定量~(13)C-NMR谱表征蔗渣碱木素结构

从蔗渣纸浆黑液中制出纯蔗渣碱木素，然后测定其定量13C-NMR谱．图谱分析表明，蔗渣碱木素主要由紫丁香基，愈创木基和对羟苯基三种丙烷结构单元组成，其中未绩合的紫丁香基、愈创木基和对羟羊基含量比为2.2：1．0：1．4．蔗渣碱术素结构单元间主要以β-O－4烷基芳基醚键连接，也有一定量的非环状α-醚键存在．蔗渣碱木素中，相当部分对香豆酸类结构并非通过酯键而是通过醚键或碳双键连接于芳核上．     

改性碱木素酚醛树脂胶MLPF的合成与应用

将草木碱木素活化后与酚醛预聚体反应制备胶合板粘合剂,进行了一系列制胶和压板试验,降低了压板温度和完善了木素胶配方。     

蔗渣碱本素低温等离子体处理研究

从蔗渣纸浆黑液中分离提纯出蔗渣碱木素，然后在Ar．N_2及O_2等不同气氛下进行低温等离子体处理，得处理残存物及裂解产物。分析结果表明，在等离子体处理过程中，蔗渣碱木素有新的自由基生成．其含量随不同气氛而异，顺序为O_2＞N_2＞Ar；蔗渣碱木素处理残存物有O．N等元素嵌入，其玻璃化转变温度和热稳定性能提高；蔗渣碱木素苯丙烷基结构单元的侧链容易断裂，其木素裂解产物有较高的O和N等元素含量。     

定量^13C—NMR谱表征蔗糖渣碱木素结构

从蔗渣纸浆黑液中制出纯蔗渣碱木素，然后测定其定量＾１３Ｃ－ＮＭＲ谱。图谱分析表明，蔗渣碱木素主要由紫丁香基，愈创木基和对羟苯基三种丙烷结构单元组成，其中未缩合的紫丁香基，愈创木基和羟苯基含量比为２．２：１．０：１．４。蔗糖碱木素结构单元间主要以β－Ｏ－４烷基芳基醚链连接，也有一定量的非环状α－醚键存在，蔗渣碱木素中，相当部分香豆酸类结构并通过酯键而是通过醚键或碳碳双键连接于芳核上。     

黑液和碱木素在石油工业中的应用

本文综述了碱法制浆黑液以及碱木素在石油工业中的应用。黑液可以直接作为低粘度稠油的驱油剂,也可作为高粘度稠油的降粘剂。与蒸汽驱或蒸汽吞吐配合使用,可显著地提高稠油的采收率。从黑液中分离出的碱木素,可用作钻井泥浆添加剂、注水或注蒸汽采油的堵水剂和调剖剂、表面活性剂驱油的牺牲剂、污水处理的絮凝剂等。在石油工业中充分利用碱法制浆黑液和碱木素,对解决黑液污染问题,降低油田化学剂成本,具有重要意义。     

麦草碱木素酚化改性及其制备LPF胶粘剂工艺研究

利用碱性条件下酚化改性的麦草碱木素代替部分苯酚制备了高木质素/苯酚比例和胶粘强度高的木质素酚醛树脂(LPF)胶粘剂.利用傅立叶红外光谱(FT-IR)和凝胶色谱(GPC)研究了麦草碱木素在碱性条件下酚化改性前后的结构变化.FT-IR分析表明,麦草碱木素发生了酚化反应,伴随着酯基的断裂和甲氧基的脱落;GPC结果显示,木质素平均分子量降低,分子量分布范围变宽.接着,研究了木质素/苯酚比例、氢氧化钠浓度、甲醛/木质素比例、酚化温度、酚化时间、缩聚温度、缩聚时间等反应工艺参数对LPF胶粘剂性能的影响,优化了麦草碱木素酚化改性制备LPF胶粘剂的反应工艺参数.最后,比较了反应工艺参数优化的LPF胶粘剂与传统PF胶粘剂的各项性能,结果显示,麦草碱木素酚化改性后代替70 % 的苯酚制备得到的LPF胶粘剂的胶粘强度与传统PF胶粘剂相近.     

草浆造纸黑液改性制备木质素酚醛树脂结合剂

以草浆造纸黑液为研究对象,通过对木质素的分离、提纯及对其酚羟基、羟甲基化改性,制备了木质素酚醛树脂结合剂。选择双氧水+稀土为催化剂,确定了其最佳的制备反应条件和试样成型工艺条件。所合成的木质素酚醛树脂结合剂,可以用于A1     

一种高耐热酚醛树脂的合成及表征

合成了一种新型高耐热酚醛树脂,并对其结构和性能进行了分析。研究发现,这种高耐热酚醛树脂对金属有良好的粘接性能,通过增韧改性可以进一步提高粘接强度;通过TG/DTA热分析手段,对合成过程中催化剂的加入量进行定量研究发现,当催化剂为树脂质量的12.5%时,合成树脂的耐热性能达到最佳,其粘接性能也非常优良。而且,用红外吸收光谱对这种新型高耐热酚醛树脂进行了表征,并确定了树脂的基本结构。     

Adhesives from Waste Paper by Means of Phenolation

Recently the effective use of woody materials has been of interest from the viewpoint of forestry preservation. Newsprint is one of the most abundant of woody materials which are discarded into the environment after use. They would be, however, easily recovered from the market.

The application of phenolation to cellulosic materials is one possibility for the utilization of waste papers. Phenolation is a newly-established method by which lignocellulosic materials are completely converted to substances soluble in some polar organic solvents.

Waste newsprint is subjected to phenolation in the presence of an acidic catalyst. The phenolated product was then methylolated in order to prepare alkaline curable adheisve resins. The chemical characteristics of the phenolated products were studied and the properties of plywood adhesives from them were evaluated. The results indicated that cellulose decomposed and reacted with phenol, producing complicated compound having a phenolic moiety during phenolation and that the compound reacted with formaldehyde, leading to resinous substance which could be thermoset.

The adhesives from the resins of phenolated newsprint provided comparable properties to a commercial phenolic resin in cure behavior, resin viscosity and tensile bond strength. The products of cellulose phenolation, therefore, are expected to be a source of wood adhesives comparable with phenolic resins.     

Eco-Friendly Adhesives Based on Tannin and N,N-Bis(2-Hydroxy-Ethyl) Fatty Amides (HEFAs) from Non-Traditional Oils for Wood Bonding

Abstract

Wood adhesives were formulated using tannin and N,N-bis(2-hydroxyethyl) fatty amides (HEFAs). The natural tannin-based adhesives can be used to replace formaldehyde-based adhesive systems and thereby reduce formaldehyde and volatile organic compound (VOC) emissions from adhesives used for plywoods. Performance properties of the adhesively bonded wood joints viz., tensile strength, impact strength and chemical resistance were measured. N,N-bis(2-hydroxyethyl) fatty amides (HEFAs) from non-traditional oils were mixed with a pure tannin-based adhesive as a crosslinker, and this increased the tensile strength, impact strength and chemical resistance of wood joints. The results revealed that a high performance and eco-friendly adhesive system for wood can be successfully formulated using tannin and HEFA.     

预水解强度对相思木硫酸盐法制浆黑液性质的影响

经水热预水解技术处理木质纤维素,木片的主要成分发生变化,对后续的化学制浆性能及制浆黑液性质带来影响。本实验采用不同预水解强度（P因子）处理相思木片,并对其硫酸盐制浆行为和黑液性质进行分析。研究结果表明,随着P因子的增大,粗浆得率和细浆得率逐渐降低;浆料的卡伯值逐渐升高。当P因子＜200时,水解后木片的黑液固形物含量由空白组的138.48 g/L升高到162.86 g/L;木素含量由58.57 g/L升高到72.68 g/L;残碱量由4.37 g/L迅速降低到2.07 g/L。当200＜P因子＜600时,黑液固形物含量由162.86 g/L降低到142.71 g/L;黑液中木素含量由72.41 g/L降低到59.16 g/L;残碱量由2.07 g/L降低到1.26 g/L。当P因子＞600时,黑液中固形物含量由142.71 g/L升高到156.95 g/L;木素含量由59.16 g/L升高到62.16 g/L;残碱量由1.26 g/L升高到1.37 g/L。不同条件下,黑液中无机物含量变化不大;黑液固形物的热值由对照组的13.71 MJ/kg提高到14.63~15.09 MJ/kg。     

Investigation and Characterization of Lignin Precipitation in the LignoBoost Process

Lignin of high purity can be separated from black liquor using the LignoBoost process, of which the overall efficiency is largely dependent on the precipitation yield of lignin, which depends on the properties of black liquor and process conditions. In this paper, the influences of process conditions on the precipitation yield of lignin from mixed hardwood/softwood black liquor were investigated. The Klason and standard UV method were used to determine lignin concentration. The chemical and structural properties of lignin were also analyzed. The results showed that the precipitation yield of lignin increased along with a decrease in pH and temperature, or with an increase in the ion strength of black liquor, and the yield was lower when mixed softwood/hardwood black liquor was used. It also showed that at a higher precipitation yield the precipitated lignin had a lower average molecular weight but had higher methoxyl and phenolic hydroxyl content.     

乙酰溴法对小兴安岭碱法杨木黑液提取物成分的研究

衍生化后的还原裂解(DFRC)法作为木质素结构解析的新方法,可以对碱法杨木黑液提取物中大分子结构的β-O-4醚键和α芳基醚键实施选择性的高效断裂.实验采用DFRC法对碱法萃取的杨木木质素进行降解,通过GC及GC-MS,分析研究了小兴安岭碱法杨木黑液提取物的成分和结构.结果表明:碱法杨木黑液提取物中主要包括4类化合物:B...     

Effects of Solvation and Ionization on 13C NMR Spectra of Lignin Model Compounds,Spruce Milled Wood Lignin and Kraft Lignin

The effects of alkali and polar aprotic solvent on the aromatic carbons signals in ¹³C NMR (Carbon-13 nuclear magnetic resonance) spectra of lignin model compounds and spruce milled wood lignin (MWL) were studied. It was found that in 1 M aqueous NaOH signal shifts of C-1 and C-4 carbon atoms in the aromatic ring were the most noticeable in lignin models with free phenolic hydroxyl groups, which are ionized under the conditions. A similar effect in the spectra of the studied model compounds was observed in 0.5 M aqueous NaOD-deuterated dimethyl sulfoxide (DMSO) mixture (DMSO: water ratio 3:7 v/v). The model data help explaining changes in the ¹³C NMR spectra of MWL and lignin in situ dissolved in spruce kraft black liquor caused by ionization. In the ¹³C NMR spectra of spruce black liquor the signals of phenolic and non-phenolic lignin units are clearly separated and do not overlap with the signals of the carbon atoms of carbohydrates and other aliphatic products of wood degradation. The data obtained are useful in understanding the important role of solvation and ionization processes leading to lignin solubilization.     

Preparation and performance of lignin–phenol–formaldehyde adhesives

Steam explosion lignin phenol formaldehyde (SEL–PF) adhesives were prepared by ternary gradual copolymerization. The parameters for the phenolate of steam explosion lignin (SEL) and preparation of SEL–PF adhesives were optimized. Under the optimum phenolate conditions, the phenolic hydroxyl content of lignin increased by 130%, whilst the methoxyl content was reduced by 68%. The SEL–PF adhesives were used to prepare plywoods by hot-pressing. The pH value, viscosity, solid content, free phenol content and free formaldehyde content of SEL–PF adhesives were investigated. The bonding strengths of the plywoods glued with SEL–PF adhesives were determined. The maximum SEL replacement percentage of phenol reached 70 wt%, and the properties of adhesives and plywoods met the Chinese National Standard (GB/T 14732-2006) for first grade plywood.     

Hydropyrolysis of kraft hardwood and softwood black liquor

The hydropyrolysis of hardwood and softwood derived black liquor was studied to develop material balance data and to investigate the potential yield of phenolic oils that might be obtained as chemical by-products of a kraft pulp mill. Hydropyrolysis reactions on softwood liquors were found to be more efficient in char formation than those on hardwood liquors. The yield of extractible phenolic oils was low, around 20–30 percent of black liquor organics, but the yields of simple phenols determined by gas chromatography were found to be even lower at 1–5 percent on black liquor organics.