漆酶/丁香酸甲酯处理未漂KP浆的SEM和GPC分析

采用扫描电镜(SEM)和凝胶渗透色谱(GPC)技术,研究漆酶和漆酶/丁香酸甲酯(MS)处理前后未漂硫酸盐浆(KP浆)纤维表面形态结构和浆中木素分子质量及其分布的变化,探讨了用漆酶和漆酶/MS处理KP浆,提高浆张湿抗张强度的相关机理。研究结果表明:与空白样相比,经漆酶处理后,纸浆中木素平均分子质量降低,纤维表面出现"黏结"现象;而MS协同漆酶处理后,纸浆中木素的缩合程度及纤维间的"黏结"面积增大;漆酶和漆酶/MS处理后的浆样再经过加热干燥处理,木素的缩合程度和纤维"黏结"面积进一步增大。木素的缩合程度和纤维表面呈现的"黏结"现象,与漆酶和漆酶/MS处理纸浆提高其湿抗张强度密切相关。     

漆酶处理对黄麻纤维木质素结构的影响

采用二氧六环/水溶液抽提制取黄麻纤维木质素,再用漆酶对其处理。利用凝胶渗透色谱测定漆酶处理前后黄麻纤维木质素的分子量及分布,并通过元素分析、红外光谱、核磁共振氢谱对漆酶处理前后黄麻纤维木质素的结构进行分析。结果表明：黄麻纤维木质素经漆酶处理后,数均分子量和重均分子量增大,酚羟基含量减少,酚型结构的木质素发生聚合反应,分子量的分布范围变宽;经漆酶处理后,黄麻纤维木质素中紫丁香基结构单元含量减少,醇羟基和总羟基含量增加,羰基含量增加。     

漆酶对不同漂段纸浆催化氧化木素的效果研究

以未漂硫酸盐桉木浆(Sp浆)、氧脱木素桉木浆(O浆)、H_2O_2漂白桉木浆(P浆)作为不同漂段原料,探讨漆酶-谷氨酸体系对不同漂段纸浆的催化效果。结果表明,漆酶催化总体上可使纸浆的卡伯值增大,纸浆的白度随之下降;漆酶协同谷氨酸可催化氧化纤维表面木素与相邻纤维上的木素发生自由基偶合反应,同时使纤维表面的微细纤维暴露出来,两者共同作用使相邻纤维形成更好的结合力,使纸浆的强度性能大幅度提升;谷氨酸可通过漆酶催化氧化作用连接到木素上,增加纤维原料中的羧基含量,Sp浆、O浆、P浆羧基含量分别较未处理纸浆提高20%、50%、43%。     

可降解黄麻/PBS复合材料的结构与力学性能

为解决当前环境污染和可持续发展问题,采用模压成型工艺制备可降解黄麻/PBS复合材料,通过拉伸、弯曲性能测试、红外分析和SEM观察,探讨纤维含量和碱处理对材料性能的影响。结果表明:随着纤维含量的增加,复合材料的拉伸强度先增大后减小,在纤维含量为10%时达到最大值,比纯PBS提高了30.1%;拉伸模量、弯曲强度和弯曲模量均随纤维含量的增大而提高,在纤维含量为30%时分别比纯PBS提高了24.2%、185.5%和107.7%。碱处理后黄麻纤维表面杂质被去除,表面部分刻蚀变粗糙,复合材料的综合力学性能得到提高,其中弯曲模量提高显著,比未处理的黄麻复合材料提高了58%。     

竹原纤维酶处理的纤细化效果

为了探讨竹原纤维酶处理纤细化的有效方法,应用漆酶、精练酶及精练酶+漆酶二步法经正交设计对已制得的竹原纤维进行纤细化处理试验,测定酶处理后竹原纤维的细度变化率、木质素含量及强度。结果表明:精练酶去除木质素的效果比漆酶好,而精练酶+漆酶二步法处理的效果均较精练酶或漆酶单独处理为好,二步法处理后竹原纤维的细度变化率为51.33%,木质素含量从原来的18.98%降为5.49%。     

Changes in composition,appearance, physical,and dyeing properties of jute yarn after bio-pretreatment with laccase,xylanase, cellulase,and pectinase enzymes

Bio-preparation is a developing and promising method for lowering the consumption of chemicals specially in wet finishing where plenty of these compounds are used. In this study, samples of jute yarns were bio-finished by cellulase, xylanase, pectinase, laccase enzymes, and their mixtures. Then, they were scoured, bleached, and dyed with basic and/or direct dyes in conventional methods. Samples were analyzed by ATR-FTIR spectroscopy, reflective spectrophotometer, mechanical tester, and then compared. FTIR peaks of enzymatic-treated samples showed aldehyde absorption peaks, and also changes in carbonyl groups of hemi-cellulose and aromatic –CH– out of plane vibration in lignin. The whiteness and brightness index values of jute yarns improved before and after bleaching. Pectinase-treated jute yarn enhanced yarn count compare to other enzymatic or NaOH treatment. All enzymatic or NaOH treatments decreased the tenacity of jute yarns. Xylanase and cellulose treatments showed lower tensile strength than others. Pectinase and laccase enzymes increased dye strength of the jute yarn that dyed by direct dye, while cellulase, xylanase, and pectinase did the same for basic dye.     

不同生物酶处理对黄麻纤维的影响

分别用漆酶、纤维素酶、木聚糖酶及果胶酶对黄麻纤维进行脱胶处理,简要分析了各种酶对黄麻纤维脱胶效果的影响,得出了各种酶处理工艺的相对最优工艺参数。各种酶的最优化工艺比较分析结果显示漆酶处理是最有效的脱胶方式。     

漆酶处理三倍体毛白杨APMP及对其中残余木素作用的研究

利用NS51003漆酶处理三倍体毛白杨碱性过氧化氢机械浆(APMP),通过分析检测处理后纸浆的打浆度和成纸物理性能探讨了漆酶处理对三倍体毛白杨APMP抄造性能的影响。实验结果表明,在最佳的工艺条件下,漆酶处理APMP与未经过漆酶处理纸浆相比,抗张指数和耐破指数稍有升高,而撕裂指数提高了16mN·m2/g,酸溶木质素含量稍有升高,Klason木质素含量相对降低;漆酶处理三倍体毛白杨APMP主要降解纸浆中纤维表面的木素,对纤维内部影响较小。     

臭氧对非木材纤维漂白和改性作用研究进展

综述了臭氧对非木材纤维纸浆的漂白和改性作用机理及研究进展。主要介绍了臭氧对稻麦草浆、蔗渣浆、竹浆和棉、麻纤维等非木材纤维作用前后纤维形态及性能的变化及臭氧处理前后废水中污染物含量变化等方面的研究进展,并对臭氧在非木材纤维漂白和改性方面的新进展及应用前景进行了总结与展望。     

漆酶/介体体系改性磨石磨木浆纤维表面性能分析

利用漆酶价体体系改性未漂马尾松磨石磨木浆，测定改性前后浆张的物理和光学性能，利用纤维长度、粗度分析仪、傅里叶变换红外光谱（FT-IR）和化学分析光电子能谱（ESCA）对漆酶价体体系改性前后纸浆纤维变化及表面性能进行分析，并测定了纸浆表面接触角（CA）。结果表明，漆酶价体体系改性纸浆仅在纤维的表面起作用，不会引起纤维的大幅度降解；纸浆改性过程中发生了氧化反应，羰基含量增加；改性后木素发生了一定程度的降解，纸浆表面木素含量降低；改性后的纸浆表面润湿性能提高。     

漆酶处理桉木纤维表面的电镜分析

采用扫描电镜(SEM)观察漆酶处理对桉木纤维表面形态的影响。结果表明,未经漆酶处理的纤维表面光滑;经漆酶处理后纤维表面出现孔洞,纤维分丝;漆酶处理纤维压制的纤维板表面,活化木素碎片重新固化,在纤维表面形成一层较厚的包覆层,纤维之间产生自黏合作用而结合紧密;未经漆酶处理的纤维板层间断面,主要由纤维分离形成;而漆酶处理纤维板断面,部分由纤维断裂形成,在氧气存在条件下的漆酶处理试样,此效果更为显著。     

旧报纸漆酶/介体脱墨浆表面性能分析

利用化学分析电子能谱(ESCA)、衰减全反射傅立叶变换红外光谱(ATR-IR)以及环境扫描电镜(ESEM)对漆酶脱墨浆的表面形态进行分析,并利用KAJAANI纤维长度粗度分析仪测定浆料纤维的长度、粗度,利用Pulmac渗透测定仪(Pumac Permeability Tester)测定了纤维的比容和比表面积.研究结果表明,漆酶/介体脱墨过程中可以使浆料中的木素溶出,表面木素含量降低,同时纤维表面出现微细纤维.与对照浆相比,漆酶处理后,纤维的长度、粗度变化不大,说明漆酶处理过程中,并未发生纤维的断裂,漆酶主要作用于纤维的表面,并未触及到纤维的内部.比表面积和比容均增加.     

漆酶活化木素提高未漂硫酸盐浆的湿强度

在传统的木质纤维加工过程中，增强剂可以使最终产品获得较好的机械强度，这些增强剂包括用于中密度纤维板生产的合成树脂和广泛用于纸张生产的湿强剂。由于环保和经济的原因，人们开始研究淘汰合成增强剂生产人造板和纸张的新生产工艺。漆酶催化木素氧化可以促进木质纤维间的自粘合性，本文综述了使用漆酶、漆酶／木素抽出液及漆酶／介体处理高得率未漂硫酸盐化学浆可以不同程度地提高未漂浆的湿强度，但干强度没有改善。     

黄麻伴生物含量及其对理化性能的影响

为研究黄麻伴生物含量对其断裂强度、断裂模量、甲醛用量的影响,采用称重法测试了麻纤维的化学成分含量,采用单纤维拉伸法测试了麻纤维的断裂强度和模量,采用紫外分光光度计法测试了麻纤维的甲醇用量。经分析认为黄麻纤维的伴生物含量与其理化性能所组成的系统为灰色系统,并对此系统采用灰关联法进行分析。结果表明：黄麻脂蜡质含量对麻纤维的断裂强度影响比较大,关联度为分别为 0.680;黄麻木质素含量对其模量和甲醛用量影响最大,关联度分别为 0.733和0.723。     

富木质素天然纤维素纤维的漂白

分析了木质素对富木质素纤维性能的影响,富木质素纤维的结构与纤维漂白性能的关系及漂白工艺参数对富木质素纤维白度的影响。比较了富木质素纤维与传统天然纤维素纤维在光、热作用及漂白过程中的性能变化,分析了木质素组分对经不同工艺漂白后纤维颜色以及力学性能的影响。通过比较和研究黄麻、红麻、玉米壳纤维等富木质素纤维的漂白性能,为其规模化应用提供帮助。     

漆酶处理对杨木APMP木素分子质量的影响

研究了漆酶和漆酶/介体体系处理对三倍体毛白杨APMP性能的影响.采取酶解-弱酸解两段法分别从APMP原浆和生物处理后的纸浆中分离木素.为了使木素在凝胶渗透色谱流动相四氢呋喃中能完全溶解,对所有试样进行了卞基化处理.利用凝胶渗透色谱分析仪获得了木素的分子质量分布曲线,并计算出数均分子质量和质均分子质量,进而比较了漆酶和漆酶/介体体系处理的效果和差异.     

漆酶作用下5-5′结构木素模型化合物与对-羟基肉桂酸的脱氢聚合反应

具有5-5′结构的木素结构非常稳定,难以在制浆过程和废水处理中降解,但酚型5-5’结构能在漆酶的作用下发生聚合。为了了解在漆酶的催化作用下5-5’结构型木素结构与对-羟基肉桂酸之间的共聚性能,进而为制浆废水中木素的酶催化絮凝技术的开发提供理论基础,本文研究了在漆酶催化作用下,对-羟基肉桂酸与5-5’结构木素模型物（脱氢二香草醇）的聚合反应。应用凝胶渗透色谱（GPC）测定了聚合产物的相对分子量,采用红外光谱、核磁共振技术探讨了对-羟基肉桂酸与5-5′结构木素模型物的脱氢聚合产物的化学结构。研究结果表明：在漆酶催化作用下,对-羟基肉桂酸与5-5′结构木素模型物发生脱氢聚合反应,形成典型的DHP。聚合后相对分子质量明显增大,相对分子量Mn由306提高到2106。结构单元之间的连接方式主要是通过β-O-4、α-O-4、β-β等。     

The comparison of chemical and structural differences of Caribean pine (Pinus caribea L.) wood and bark lignin

The presented paper deals with some chemical properties of Caribean pine wood and bark lignin. In order to obtain necessary data, the following operations and analyses were performed: dioxane lignin isolations, determination of Klason lignin, determination of methoxyl, carboxyl and phenolic hydroxyl groups in dioxane lignins and the nitrobenzene oxidation of both compared lignins and of the risidues remaining after dioxane lignins extraction. The oxidation products were analysed by GLC. The experimental data show that there are moderate differences between compared lignins.     

A Comparison of a New Method Mediated by Molybdenum Complex with an Enzymatic Method for Bleaching Flax Fibers

In the last years, the interest in bast fibers for textile products has been growing in line with the necessity for new added-value products. The attention has focused on the research in developing of different methods of processing natural fibers. The main goal of this work was to compare two methods for fiber’s degumming. One method used the molybdenum complex for degumming and the other is an enzymatic one with laccase as catalyst. The physical–mechanical parameters were in the same range for both methods, while the lignin contt was smaller for the molybdenum complex—peroxide process than for the treatment with laccase—peroxide system. The characterization using FT-IR spectroscopy and thermogravimetry also suggest that the treatments with molybdenum complex degraded more lignin than the enzymatic treatments. The crystallinity index of bleached fibers using the system molybdenum complex was higher than for the fibers treated with enzymes while the degrees of whiteness were somehow lower but in the acceptable range.     

A comparison of some chemical and physical properties of alkali lignins from grass and lucerne hays before and after digestion by sheep

The chemical and physical properties of alkali lignins from a grass hay and a lucerne hay were studied, before and after digestion by sheep. A greater proportion of the total grass lignins was dissolved by alkali than with the lucerne lignins but digestion increased this proportion with both species. Of the lignin dissolved by alkali, less of it was precipitated on acidification when faeces (50–70%) were compared with the undigested hays (86–92%). Extraction of lignins with boiling alkali produced a lignin with the smallest amount of amino acids but considerably altered the chemical structure as revealed by nuclear magnetic resonance (n.m.r.). Trypsin treatment of a cooler alkali extract was less effective in reducing amino acid contamination but did not alter the structure. Compared with the grass alkali lignins, the lucerne lignins had more total but fewer aromatic protons, fewer groups reacting with N-2,6-trichloro-p-benzoquinone imine, ionisable hydroxyl groups and fewer methoxyl groups. On Sephadex G-200 gel chromatography, three peaks were apparent with the lucerne, but only two with grass lignins. Both plant lignins showed large amounts of highly shielded n.m.r. protons but there were more with lucerne. Infrared spectra suggested that they were probably due to methyl groups. Digestion had very little effect on the n.m.r., ultraviolet or infrared spectra or the molecular weight distribution of the isolated lignins. It may have reduced the numbers of groups, reacting with N-2,6-trichloro-p-benzoquinone imine with the grass and two maize samples examined, but appeared to have the opposite effect with the lucerne.