木质素在农业中的研究进展

对造纸黑液木质素在农业中应用的研究现状进行了综述,包括木质素在肥料、农药、饲料、植物生长调节剂、液体地膜、土壤改良剂等方面的应用概况。这些技术成果是木质素农业化利用的重要基础。木质素来源丰富,具有广阔的应用前景,加强研究与应用开发对促进资源充分利用、环境保护与制浆造纸协调持续发展意义重大。     

非金属矿加工专利文摘(国内)

一种复合填料及其制备方法;一种含有毒死蜱的颗粒剂及其制备方法;陶土生产路边石、地砖;无孔分相饰面材料及其制备工艺;造纸填料用改性剂、造纸填料以及制备方法和应用;立窑水泥煅烧节能型添加剂;用蛇纹石制取轻质氧化镁、白炭黑及回收硫酸铵的方法;天然盐湖钠芒硝资源的芒硝碱兑合残卤碳化生产纯碱方法。     

富阳造纸污泥处理用上新技术

<正>近日,依托北京松源兴业生物技术有限公司和中国农业科学院农业资源与农业区划研究所,富阳市又攻克一项造纸污泥处理新技术。该项技术根据造纸污泥既含有大量纤维素类有机质和氮、磷、钾等植物养分,又含有微量重金属和病原     

国内简讯

废纸脱墨过程中表面活性剂及其助剂的应用世界上造纸的原料95%为木材,在目前木材资源紧张的形势下,以废纸为原料造纸的比例日趋上升。既节省了木材资源,又可减轻环境污染,是造纸工业很有前途的发展方向。然而大多数废纸为印刷品,用来生产略为高档的产品,必须脱除原料中的油墨。表面活性剂用于废纸脱墨是其在造纸工业中主要用途之一。     

植物内生菌及其次生代谢活性物质多样性的研究进展

植物内生菌是一种新型的微生物资源,具有重大的研究意义和潜在的应用价值,近年来已成为微生物资源研究的热点之一.对植物内生菌及其次生代谢活性物质多样性的研究进展进行了综述.     

羧甲基淀粉开发前景

综述了以淀粉为原料开发羧甲基淀粉的生产工艺，以及其在造纸，纺织，印染，医药，废水处理，选矿，铸造，胶粘剂等领域的应用。同时阐述了开发羧甲基淀粉的资源和发展概况以及市场前景。     

羧甲基淀粉的开发前景

综述了以淀粉为原料开发的羧甲基淀粉的生产工艺 ,以及其在造纸、纺织、印染、医药、废水处理、选矿、铸造、胶粘剂等领域的应用 ,对开发羧甲基淀粉的资源和发展概况以及市场作了概述     

羧甲基淀粉的开发前景

综述了以淀粉为原料开发的羧甲基淀粉的生产工艺，以及其在造纸、纺织、印染、医药、废水处理、选矿、铸造、胶粘剂等领域的应用，对开发羧甲基淀粉的资源和发展概况以及市场作了概述。     

大学生科技创新能力培养实践思考

从植物资源学实验教学及其拓展平台定位、植物资源学实验教学及其拓展平台关系、植物资源学实验教学拓展实践、特产经济植物概念渗透与学生科技创新能力培养等方面探讨创新型人才培养的植物资源学教学方法。植物资源学实验教学拓展实践是植物资源学教学有益的补充,将课程教学与实践联系起来,学生更好地理解课程教学所学知识,培养了学生综合素质。在课程教学、指导学生申请大学生创新性实验项目、大学生参与科研项目中培养学生科技创新能力。     

造纸湿强剂的研究进展

简要介绍了造纸湿强剂的增强机理,讨论了湿强剂的应用及其研究进展,并探讨了今后造纸湿强剂的研究发展方向。     

Extraction and Characterization of Hemicelluloses and Cellulose from Oil Palm Trunk and Empty Fruit Bunch Fibres

Abstract

The cell walls of oil palm trunk fibre and empty fruit bunch (EFB) fibre were initially extracted with 5% NaOH at boiling for 2 h, which removed 17.3% and 15.2% hemicelluloses, respectively. Further extraction of the delignified palm trunk and EFB fibre was conducted with 10% NaOH at 20°C for 16 h and 24% KOH-2% H₃BO₃ at 20°C for 2 h. This resulted in the release of 11.9%, 13.5%, 12.7% and 14.9% residual hemicelluloses, respectively. The cellulose content, isolated by 24% KOH-2% H₃BO₃ from the two fibre samples, was found to be 41.3-41.7%, most of which was relatively free of associated lignin and hemicelluloses. The hemicelluloses, extracted with 5% NaOH from the lignified palm trunk fibre and EFB fibre, contained relatively high amounts of xylose, and minor arabinose and rhamnose than the hemicelluloses, extracted with 10% NaOH and 24% KOH-2% H₃BO₃ from the delignified fibres. While the hemicelluloses, extracted with 10% NaOH and 24% KOH-2% H₃BO₃ from the delignified palm trunk and EFB fibre, contained slightly more galactose, glucose, and mannose than the hemicelluloses, extracted with 5% NaOH from the lignified fibres. Further studies implied that the hemicelluloses, extracted with 5% NaOH from the lignified fibres, were more linear and acidic and had a large molecular size (weight-average, 17,400-22,900), together with comparatively high associated lignins (12.0-15.7%). Which were found to be linked to hemicelluloses mainly via syringyl unit. On the other hand, the hemicelluloses, extracted with 10% NaOH and 24% KOH-2% H₃BO₃ from the delignified fibres, were more branched but less acidic and had a comparatively small molecular size (weight-average, 6,600-10,800), together with trace amounts of associated lignin (0.3-1.1%). The hemicelluloses in the cell walls of palm EFB had a higher degree of polymerizaton than the hemicelluloses in the cell walls of palm trunk fibre as indicated by the molecular-average weights, ranging from 7,200 to 22,900, and from 6,600 to 17,400, respectively.     

Softening of wood polymers induced by moisture studied by dynamic FTIR spectroscopy

The softening of the wood polymers is very important in the utilization of wood fiber products. To better to understand how the hemicelluloses interact with the other wood polymers in the fiber ultrastructure and contribute to the mechanical properties of the wood, their softening inside the cell wall of pulp fibers was studied by dynamic FTIR spectroscopy under humid conditions. The two hemicelluloses of spruce, glucomannan and xylan, exhibited different softening behaviors indicating a different organization of the two hemicelluloses inside the cell wall. Lignin in mechanical pulp showed a more viscoelastic behavior already under dry conditions than the polysaccharides of the cell wall. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2032–2040, 2004     

制浆造纸厂实行生物炼制的可行性

生物炼制是解决石化资源紧缺的新途径,而制浆造纸厂是生物炼制技术最容易实现产业化的平台。文章综述了制浆造纸厂中半纤维素、木质素、松节油、妥尔油等废弃生物质进行生物炼制的可行性及存在的问题,并对发展前景作了展望。     

Fractional Separation of Hemicelluloses and Lignin in High Yield and Purity from Mild Ball-Milled Periploca sepium

Abstract

A novel three-step procedure for separation of hemicelluloses and lignin with high yield and purity was proposed in this study, where wood is mildly milled and successively extracted to produce three hemicellulosic and lignin fractions representing the total hemicelluloses and lignin in wood. The sequential treatments of the mild ball-milled Periploca sepium with 80% aqueous dioxane containing 0.05 M HCl at 85°C for 4 h, DMSO at 85°C for 4 h, and 8% NaOH at 50°C for 3 h resulted in a total release of over 85% of the original hemicelluloses and 86% of the original lignin. In particular, approximately 36% of the original hemicelluloses and 50% of the original lignin were separated during the first mild acidolytic hydrolysis process after low intensity milling. The structure of the acidic dioxane-, DMSO-, and alkali-soluble hemicellulosic and lignin fractions were elucidated using wet chemical analysis, FT-IR, and solution-state ¹H, ¹³C, and ³¹P NMR techniques. Results showed that both the mild ball milling and the mild acidolysis under the conditions given did not affect the separated lignin macromolecular structure. On the other hand, the mild acidolytic hydrolysis condition did cause substantial hemicellulosic depolymerization exception for a significant cleavage the ether linkages between lignin and hemicelluloses. The acidic dioxane-soluble lignin fraction was structurally different from the DMSO- and alkali-soluble lignin preparations and may originate mainly from the primary wall, while the alkali-soluble lignin preparation was mainly released from the secondary wall of Periploca sepium. Furthermore, it was found that the acidic dioxane-soluble hemicelluloses mainly contained more branched and less acidic arabinoxylans, and the 8% NaOH-soluble hemicellulosic fraction H₃ was both less branched and less acidic in structure, whereas the DMSO-soluble hemicelluloses were more acidic but less branched and consisted mainly of 4-O-methylglucuronoarabinoxylan.     

Interaction of Hemicelluloses with Monolignols

Abstract

Interactions of hemicelluloses, xylan and glucomannan, with monolignols, coniferyl alcohol and sinapyl alcohol, and their glucosides, coniferin and syringin, were investigated by surface plasmon resonance analysis. Hemicelluloses with different aldehyde contents, prepared by sodium periodate oxidation, were immobilized onto carboxymethyl–dextran–coated gold plates by reductive amination. The interaction of the hemicelluloses with monolignols was evaluated as weight gain of the hemicelluloses at neutral pH. Both hemicelluloses adsorbed the monolignols in much larger amounts than the corresponding glucosides. The adsorption tendency was independent of aldehyde content. These results suggest the hemicelluloses have higher affinities to the aglycons than the glucosides. Thus, the interactions of the hemicelluloses with monolignols are primarily the result of hydrophobic interactions. However, binding constants were not estimated because of the low solubility of the monolignols in the aqueous buffered solution.     

Mathematical Model for Predicting the Dissolution Behaviors of Hemicelluloses During Cold Caustic Extraction Process

Cold caustic extraction (i.e., CCE) is widely used in mill practice for hemicelluloses removal, and the parameters of which can significantly affect the hemicelluloses dissolution. Therefore, the dissolution behaviors of hemicelluloses under different CCE process parameters have been investigated. The results showed that with the temperature increases, the dissolution of hemicelluloses also increases. However, the effect of alkali content showed complicated, since lower content (<9.0 wt %) was good for the swelling of fibers (i.e., good for hemicelluloses dissolution), but higher content (>9.0 wt %) would accelerate the competing hydration of sodium ions with water and thus limited the dissolution of hemicelluloses. Besides, a mathematical model has been also developed for predicting the hemicelluloses dissolution during CCE process, which can provide a good guidance for enhancing the purification efficiency in the CCE process operation. © 2018 American Institute of Chemical Engineers AIChE J, 65: 13–17, 2019     

半纤维素的醚化改性

简单介绍了半纤维素的化学组成及结构特点,对近十年来半纤维素的醚化改性的研究进展进行了综述,主要介绍了半纤维素的羧甲基化、甲基化、季铵化等的醚化反应。展望了半纤维素醚化改性的发展前景。     

半纤维素作为造纸助剂的研究进展

综述了半纤维素作为造纸助剂的研究进展,主要包括不同半纤维素添加量对纸张性能的影响、添加玉米秸穰对纸张性能的影响、半纤维素作为打浆助剂和湿部添加剂的研究等。并概述了近年来半纤维素改性的研究。     

农业秸秆半纤维素分离及纯化技术研究进展

我国是农业大国,每年有大量的农业秸秆没有完全充分利用。农业秸秆中半纤维素含量一般在28%～35%之间。在秸秆细胞壁中,半纤维素与木质素之间有化学键的联接,与纤维素之间有氢键的联接,因此限制了半纤维素从细胞壁中的分离。分离半纤维素的技术有化学法、机械法与化学法相结合、热处理法、膜分离等,但到目前为止还没有一种分离技术能够较完整地将半纤维素从植物细胞壁中分离出来。文章综述近年来农业秸秆半纤维素的分离技术,并提出了存在的主要问题。     

New aspects in cationization of lignocellulose materials. III. Influence of delignification on reactivity and extractability of TMAHP–hemicelluloses

Beech sawdust samples with different lignin content were alkylated with 3-chloro-2-hydroxypropyltrimethylammoniumchloride (CHMAC). The yields and the degree of subtitution of trimethylammonium-2-hydroxypropyl (TMAHP) samples were similar. Differences were found in extractability of hemicelluloses from this materials both with water and dilute alkali. To obtain the maximum yield of TMAHP–hemicelluloses (ca. 90% of the amount originally present), it is sufficient to remove about 50% of lignin. The lignin component does not influence the reactivity of hemicelluloses. The isolated hemicelluloses differ only in the distribution of functional groups and extractability.