亚麻木质素和果胶质在脱胶漂白中变化规律探讨

通过单因素试验,探讨了亚麻传统粗纱脱胶漂白工艺和酶精练工艺中木质素和果胶质变化规律,结果表明:酸洗、煮练、氯漂、氧漂中的有效成分质量浓度的增加、处理温度的升高、处理时间的延长,均有助于木质素和果胶质的去除,其中氯漂对果胶质和木质素的去除效果最好,尤其是当氯漂时间延长到60 min时,粗纱中的果胶质和木质素含量的去除率分别可达93.15%、76.53%,而且在脱胶漂白工艺中果胶质比木质素较易去除;经酶精练优化工艺处理后亚麻纱线白度为73.8,粗纱中果胶质去除率40.51%,木质素去除率73.88%。     

螯合剂在亚麻酶精练工艺中的作用

研究螯合剂对亚麻粗纱或织物酶精练效果的影响。实验表明，不论酶的种类、酶的用量、处理时间条件如何变化，螯合剂对去除亚麻纤维上的果胶、木质素均有明显的促进作用。     

基于果胶复合酶的亚麻粗纱煮练工艺优化

针对传统化学法亚麻粗纱煮练工艺对纤维损伤大、环境污染严重等问题,为提高亚麻粗纱的品质,以黑曲霉102-ZL为菌种,以麸皮和稻草粉为主要原料,采用固体发酵方法生产果胶复合酶,浸提后将粗酶提取液用于亚麻粗纱煮练.以煮练后亚麻粗纱的残胶率和强力为指标,通过单因子和正交试验对亚麻粗纱果胶复合酶煮练的酶液浓度、处理温度、处理时间...     

复合生物酶法煮练亚麻粗纱工艺的研究

利用复合生物酶法对亚麻粗纱进行煮练操作,并采用正交试验方法研究了复合生物酶作用的pH值、时间、温度、酶的配比和用量对煮练效果的影响.通过对处理后的亚麻粗纱样品中果胶和木质素含量的分析比较,并结合生产成本的考虑,最终确定了煮练的最佳工艺参数和工艺路线,即:浴比1:10、pH值8.0、时间3 h、温度60℃、果胶酶:木聚糖酶1:4、酶用量3 g/L,渗透剂用量2 g/L.     

生物酶处理对亚麻/棉织物杂质的去除作用

研究了果胶酶、纤维素酶、木聚糖酶和漆酶单一及混合处理对亚麻/棉织物上果胶和木质素的去除作用及前处理效果,并与传统工艺进行了比较。结果表明,虽然生物酶前处理对织物的强力损失远低于传统的前处理工艺,但对木质素的去除率与传统前处理工艺相比还有很大差距,而且,对果胶的去除率也没有传统前处理工艺好。在前处理效果上,生物酶前处理的润湿性和麻皮去除情况与传统前处理工艺相比有一定差距。     

芽孢杆菌产碱性果胶酶的棉散纤维精练

采用自制的芽孢杆菌WSHB04202产碱性果胶酶对棉散纤维进行精练,与Bioprep 3000L果胶酶和传统碱精练进行对比,分析了自制酶对棉纤维失重率、果胶去除率、棉蜡去除率、断裂强力及染色性能的影响.结果表明,自制酶与Bioprep 3000L果胶酶的应用效果相当,酶精练后棉纤维的失重率和强力损失远小于碱精练,棉蜡去除率低于碱精练,果胶去除率及精练后棉纤维的染色性能与碱精练试样相当.     

基于亚麻粗纱的酶煮漂技术研究

研究采用果胶复合酶对亚麻粗纱煮练 ,用过氧化氢酶去除双氧水漂白后的残留双氧水 ,并采用数理统计学中正交表及方差分析 ,阐述了酶浓度、pH值、温度、时间等因素对煮练漂白的影响 ,确定了酶煮漂的最佳工艺参数和工艺路线 ,可实现无环境污染的清洁化生产。     

细胞壁组分及酶活性与清见果实囊衣绵韧的相关性

以清见杂柑为研究材料,进行定点和定期的跟踪测定,探究清见果实囊衣中果胶类物质、纤维素、半纤维素、木质素含量和果胶甲酯酶、多聚半乳糖醛酸酶、纤维素酶活性在花后120～300 d的动态变化情况,及其与清见果实囊衣绵韧程度的相关性。结果表明：囊衣胞壁物质含量在成熟后期均有下降,多聚半乳糖醛酸酶和纤维素酶活性在后期处于上升趋势,果胶甲酯酶则相反;较高水平的水溶性果胶和低水平的木质素、纤维素、半纤维素有利于清见果实良好化渣性的形成;从花后210～300 d,细胞壁中多聚半乳糖醛酸酶、纤维素酶活性高低是决定囊衣质地绵韧程度的关键因子。     

热处理对采后琯溪蜜柚果实汁胞粒化的影响及其与细胞壁代谢的关系

汁胞粒化是柚类果实采后主要的品质劣变现象。本实验以琯溪蜜柚果实为材料,研究热处理对果实贮藏期间品质的影响,探讨其抑制汁胞粒化的作用和适宜处理条件,并探究该抑制作用与细胞壁中木质素和细胞壁多糖代谢的关系。分别以35、42、49、56 ℃热水对琯溪蜜柚果实进行喷淋处理,根据果实冷藏期内汁胞粒化指数、水分质量分数、可溶性固形物和可滴定酸质量分数变化筛选较优处理温度,并评价该温度处理对果实汁胞木质素质量分数、木质素合成酶活力、细胞壁多糖含量及其降解酶活力的影响。结果表明：与其他处理相比,42 ℃热水处理15 min能够较好地延缓琯溪蜜柚果实贮藏期间汁胞粒化指数升高和水分质量分数降低,维持汁胞可溶性固形物和可滴定酸质量分数;与对照组相比,42 ℃热水处理抑制了汁胞中苯丙氨酸解氨酶、肉桂醇脱氢酶和过氧化物酶活性,减缓了木质素质量分数增加;并且抑制了纤维素酶、果胶甲酯酶、多聚半乳糖醛酸酶和β-半乳糖苷酶的活性,延缓了纤维素和半纤维素含量的升高、共价结合态果胶含量降低、离子结合态果胶和水溶性果胶含量的增加。因此,42 ℃热水喷淋处理可有效延缓采后琯溪蜜柚果实汁胞粒化等品质劣变现象,其减缓汁胞粒化的作用可能与木质素合成相关酶和细胞壁多糖降解酶活性受抑制,延缓汁胞木质化、纤维化和果胶降解,使细胞壁组分和结构得到较好的维持有关。     

角质酶和果胶酶复合酶对棉针织物的精练研究

分别用角质酶、果胶酶、角质酶/果胶酶复合酶对棉针织物进行精练,考察精练前后纤维表面形态以及果胶去除率、棉蜡去除率、强力、润湿性变化.结果表明:角质酶(1 500 U/L)/果胶酶(12.75 U/L)复合酶的果胶去除率、棉蜡去除率分别达到79.1%和43.0%,比单独使用果胶酶有所提高,说明两种酶对棉纤维的精练具有一定的协同作用.     

Influence of various retting methods on properties of kenaf fiber

Gum, as the important noncellulosic tissue present in kenaf fiber, has a close relation with downstream processing and product properties, so the predominant task in pretreatment of kenaf fiber for textile application, retting, is to remove gum including pectin, hemicellulose, lignin, and other impurities without damage to cellulose fiber. The traditional retting method is water retting; that is, the harvested kenaf bast is soaked in natural water (rivers or tanks) in which indigenous bacteria attack the gum in an anaerobic process, yielding much water pollution. Currently, much interest has been focused on various retting methods in order to seek one environmentally-friendly method. Therefore, microbe, chemical, water, and microbe–chemical rettings are performed in this experiment. Retted kenaf fibers at optimal conditions of various retting methods are then characterized and compared by light microscopy and indices consisting of residual gum content, fineness, tenacity, elongation, and softness. In addition, chemical oxygen demand (COD) is also tested. The results indicate that microbe retting induces higher residual gum content and lower elongation but better tenacity and softness and finer fiber; chemical retting gives lower tenacity and thicker fiber; water retting produces weak, poor quality fiber; and microbe–chemical retting produces moderate indices.     

Removal of Heavy Metal Ions from Aqueous Solutions Using Lignocellulosic Fibers

Abstract

Spruce, coconut coir, sugarcane bagasse, kenaf bast, kenaf core, and cotton were tested for their ability to remove copper, nickel and zinc ions from aqueous solutions as a function of their lignin content. The fibers were analyzed for sugar and lignin content and extracted with di-ethyl ether, ethyl alcohol, hot water, or 1% sodium hydroxide.

The order of lignin content in un-extracted fibers is coconut coir > spruce > kenaf core > bagasse > kenaf bast > cotton. The fiber with the highest level of heavy metal removal was kenaf bast that had a very low level of lignin, showing that removal of heavy metals does not correlate with lignin content. Cotton, with about 1% lignin, was very low in metal ion sorption while all of the fibers containing lignin did remove heavy metal ions showing that lignin does play a role in metal ion sorption. Extraction with the various solvents removed different cell wall components and did change heavy metal sorption that indicates that cell wall chemistry and architecture may also be important factors in the sorption of heavy metals from aqueous solutions using lignocellulosic fibers.     

国产剑麻基本性能测试与分析

为了提高剑麻纤维的可纺支数和可纺性,以实验方法检测国产剑麻在无处理、氯漂处理、碱液煮练下的性能。实验结果表明,剑麻纤维中果胶和木质素的含量较高,纤维刚性较大,抱合力差,处理时最好选择碱液煮练为主,可有效除去果胶和木质素。     

Effect of pH and Heat Treatment on the Binding of Calcium, Magnesium, Zinc, and Iron to Wheat Bran and Fractions of Dietary Fiber

The effect of pH and heat treatment on the binding of added food grade sources of calcium, magnesium, zinc, and iron to a standard wheat bran, cellulose, and lignin was investigated. 1% solutions of pectin and guar gum were examined for their ability to bind these metals in aqueous solution. Lignin and pectin was found to have high metal binding capacities. Metal binding to fiber was found to be pH dependent. Toasting had no effect on metal binding by cellulose, but had a significant effect on the binding of metals by lignin and wheat bran. Boiling had a significant effect on the binding of metals by cellulose, lignin, and wheat bran.     

Comparison of the performance of kenaf fiber using different reagents presoak combined with steam explosion treatment

To enhance the degumming effect of steam explosion on kenaf fiber, different chemical reagents including hydrogen peroxide (H₂O₂), sulfuric acid (H₂SO₄), and sodium hydroxide (NaOH) presoak combined with steam explosion were used and compared in this article. Distilled water coupled with steam explosion treatment and kenaf raw samples were used as control. The fiber morphology, chemical composition, crystalline structure, degree of fineness, and breaking tenacity of kenaf fibers after treatment were studied. The results showed that hydrogen peroxide (H₂O₂) performs better on removing lignin. It not only splits fibers, but also keeps the fiber’s tenacity during steam explosion treatment. Dilute sulfuric acid (H₂SO₄) performs better on hemicellulose removal, but it damages the fiber cellulose during steam explosion treatment and cause the fiber strength decrease a lot. Sodium hydroxide (NaOH) performs the best on removing hemicellulose and lignin, and splits fiber well. However, the breaking tenacity of the fiber is lower than the fiber pretreated by H₂O₂. Besides, NaOH is a pollutant to the environment. In conclusion, H₂O₂ could be considered as the most promising reagent to be used in combined presoak-steam explosion system.     

Effects of Dilute Acid Pretreatment on Chemical and Physical Properties of Kenaf Biomass

In the current research, kenaf represents an agricultural biomass that possesses enormous potential for industrial applications. Because of its complex structure, which is composed of cellulose, hemicellulose, and lignin, pretreatment process was conducted. Here, dilute acid pretreatment process was conducted, statistically using the response surface method, which included three parameters: mass of biomass (g), temperature (°C), and time (min). About 2 g of kenaf biomass was treated with 2% dilute sulphuric acid, and it was found to have higher glucose conversion (25.3%) when the process was conducted for 60 min at the temperature of 180°C. The main aim of the current research is to investigate the chemical and physical changes of kenaf biomass before and after the pretreatment. The changes could be clearly seen in the cellulose, hemicellulose, and lignin composition before and after the pretreatment, which were evaluated via TAPPI standard test methods. Morphological observation under scanning electron microscope confirmed the changes that took place on the kenaf biomass from complex to simple surface structure. Fourier transform infrared analysis confirmed the presence of cellulose, hemicellulose, and lignin contents of the kenaf biomass before and after pretreatment. Crystallinity of the treated kenaf biomass also increased from 46.6% to 70.0%, as evidenced from X-ray diffractometer analysis.     

精细化加工对大麻纤维理化性能的影响

针对大麻韧皮纤维胶质含量高、刚性大、可纺性差等问题,对其进行分步的精细化加工处理,深入分析比较每一步加工后大麻纤维的理化性能,将脱胶处理对大麻纤维造成的损伤降到最低,使大麻纤维变得更细,更干净,更柔软,提高大麻纤维的可纺性能。结果表明：精细化加工后大麻韧皮中的果胶及木质素等非纤维素物质的去除率达到93％以上,分裂度达到3000 Nm以上,纤维纵向表面光洁,拉伸断裂强度为11.02 cN/tex,抗弯刚度为0.61×10-7 cN•cm2,结晶度为81.57％。精细化加工后的大麻纤维可以在高效的棉纺设备上进行纺纱。     

红麻木质部化机浆残余木素的特性

本文对红麻本质部化机浆磺化和Ｈ２Ｏ２漂白后的残余酶解木素的特性进行了研究，研究结果表明：磺化和漂白后木素的提取率下降，残余木素的平均分子量减小，磺化后红麻木质部酸溶木素含量增加，木素中酯键和烷基芳基醚键等连接型式有一定程度的断裂，木素自由基减少，共轭羰基、邻醌结构和酚羟基有所增加，Ｈ２Ｏ２漂白可以破坏部分邻醌结构和共轭羰基，而木素中甲氧基、酚羟基含量有所上升。     

从木素物理性质比较AP及AS预处理对红麻秆芯部的作用

以红麻秆芯及经过碱性过氧化氢预处理（ＡＰ）和碱性亚硫酸钠预处理（ＡＳ）后的红麻秆芯为研究对象,分离出磨木木素,并从相对分子质量及其分布、玻璃化转移温度等方面研究了３种磨木木素的物理性质的差异。同时研究了３种料片的弹性模量同温度的关系。研究认为,在本实验条件下,ＡＳ预处理对红麻秆芯的性质有显著的作用,是制备化学机械浆较好的预处理方法;而ＡＰ预处理,对红麻秆芯的作用程度较弱。     

闪爆处理对大麻纤维的影响

针对大麻纤维手感刚硬,易折皱,染色困难等加工难题,将闪爆技术引入大麻纤维的处理,通过对闪爆处理前后大麻纤维的化学组成、表面结构、力学性能和染色性能的比较,研究闪爆处理工艺对大麻纤维性能的影响。结果表明:闪爆处理有利于大麻纤维果胶、木质素和半纤维素的脱除,特别是果胶的脱除;同时可提高大麻纤维的柔软性,改善其染色性能,但闪爆处理会损伤大麻纤维,使其强度有所降低。