壳聚糖及其降解产物黏均分子质量的测定

测定降解前、后壳聚糖的分子质量,用0．1mol·L^-1乙酸-0．2mol·L^-1氯化钠溶液做溶剂,采用黏度法进行测定。测得未降解壳聚糖[η]为407．6,分子质量约为5．7×10^5,降解180min壳聚糖[η]为26．0,分子质量约为2．9×10^4.采用黏度法测定壳聚糖的分子质量具有原料处理简单,仪器易于清洗,实验数据重现性好等特点。     

N,O-羧甲基壳聚糖的制备

本文研究了在碱性条件下,用氯乙酸对壳聚糖进行化学改性,合成了有良好水溶性的N,0-羧甲基壳聚糖。实验结果表明：壳聚糖、氢氧化钠、氯乙酸三者质量之比为1：4：4．5,温度为60℃,反应时问为5h时,所得羧甲基壳聚糖的取代度达到1．18,产率为145％。     

制约壳聚糖纤维应用的因素及解决方法

对制约壳聚糖纤维应用的主要因素进行了剖析,主要从壳聚糖纤维产量低,纤维质量不稳定,壳聚糖纤维混纺纱染色困难等因素进行了探讨;同时,介绍了为突破这些因素,目前国内外所采取的解决方法。     

醇溶剂法制备高脱乙酰度壳聚糖

采用戊醇-氢氧化钠反应体系,通过对投料比、反应温度、反应时间等影响因素研究了甲壳素的脱乙酰反应,结果表明在四流温度．反应时间1．5h,壳聚糖：NaOH：醇=1：5：11(质量比)条件下制得脱乙酰度为99．7％的壳聚糖,而传统水溶剂脱乙酰度小于50％。     

黏均分子质量为1万左右的壳聚糖制备的研究

本文着重讨论了通过过氧化氧氧化法降解制备黏均分子质量在1万左右的壳聚糖。本实验采用了正交实验设计，探讨了制备条件对产物脱乙酰度、特性黏度、水溶性等的影响。最佳制备条件为：H2O2的质量分数为4％，CH3COOH的质量分数3．5％，壳聚糖的质量分数2％，时间4h，温度50℃。最佳制备条件得到的壳聚糖脱乙酰度为88．53％，黏均分子质量为9048。实验结果基本苻合预期的要求。     

壳聚糖季铵盐阳离子改性亚麻织物染色

采用羟甲基二甲基氯化铵与伯羟基酰化N-乙酰化壳聚糖合成了低聚合度季铵型阳离子壳聚糖季铵盐(HBCC)。采用HBCC对亚麻织物整理后染色,研究结果表明,HBCC处理的亚麻织物上染率为41.0%,固色率为75.9%,水洗牢度达到5级,耐摩擦牢度达到5级。     

无甲醛耐晒固色剂QJ-02的研制

二乙烯三胺在110℃下与氯化铵反应，其产物在120℃时与双氰胺反应，调节pH值=7．5～8，加入环氧氯丙烷，经醋酸酸化合成了QJ—02无甲醛耐晒固色剂。在应用时加入壳聚糖，使棉染色织物的耐晒牢度得到明显提高。与传统的固色剂相比，干、湿摩擦牢度提高了2级，皂洗牢度提高了0．5～1级，耐晒牢度提高0．5～1级，达到了5级，染色织物的色光没有变化。     

壳聚糖涂膜保鲜杨桃的研究

研究了不同组成的壳聚糖涂膜保鲜剂对杨桃的保鲜效果。结果表明：壳聚糖涂膜剂对杨桃具有较好的保鲜效果,浸涂保鲜剂的杨桃在贮藏期间其水分、总酸和维生素C的含量均高于对照,而还原糖含量低于对照。壳聚糖涂膜保鲜剂较适宜的配方为：壳聚糖2．5％,乙酸1．5％,甘油1.0％,单硬脂酸甘油酯0.3％,水94．7％。     

微波交联CTS/GLT共混膜的制备及性能研究

以甲醛为交联剂在微波条件下交联壳聚糖和明胶，成功制备出微波交联CTS／GLT（壳聚糖／明胶）共混膜。研究了膜的力学性能、吸水性和透光率。研究结果表明，最佳制膜条件为微波功率500W，微波辐射时间1．0min，交联剂用量为壳聚糖的0．4％，壳聚糖／明胶质量比为80／20。膜的拉伸强度为56．39MPa，吸水率为1．33％，透光率为92．3％。     

壳聚糖在活性染料染羊毛织物上的应用工艺探讨

本文对壳聚糖处理过的羊毛织物用活性蓝BET染色工艺进行了探讨.讨论了壳聚糖脱乙酰度、壳聚糖浓度对羊毛染色性能的影响,并比较了经壳聚糖处理与未处理羊毛染色性能的差异.结果表明,提高处理液中壳聚糖的浓度或脱乙酰度都能提高活性染料的固色率,提高织物表面色深值K/S,而且对染色样的各项牢度影响不大.     

Influence of the molecular mass of chitosan on shrink-resistance and dyeing properties of chitosantreated wool

Wool fabrics were treated with the biopolymer chitosan under conditions which conferred shrinkresistance and dyeing improvement. In order to enhance chitosan absorption in wool, two different oxidative chemical pretreatments, hydrogen peroxide and permonosulphuric acid, were performed on wool fabrics prior to chitosan application. Chitosans of three different molecular masses, but with the same acetylation degrees of, were applied to unpretreated and oxidated wool and the influence of the molecular mass of chitosan and the oxidative pretreatment on shrink-resistance and dyeing behaviour was assessed. In conclusion, both molecular mass and oxidative pretreatment exert an influence on shrink-resistance. However, dyeing behaviour depends only on the presence of chitosan on wool fibre.     

降解壳聚糖在棉织物活性染料低盐染色中的应用

采用降解壳聚糖对棉织物进行预处理,比较处理前后棉织物活性染料染色的上染率、固色率及耐摩擦牢度,在此基础上研究低盐工艺对棉织物活性染料染色的上染率、固色率的影响。实验结果表明降解壳聚糖预处理棉织物显著改善活性染料染色性能,提高染料上染率,减少了染整加工过程中对环境造成的污染。降解壳聚糖预处理的最佳工艺条件:浸渍温度80℃、降解壳聚糖用量0.8%(owf)、浸渍时间30 min。     

Structure and properties of hemp fabric treated with chitosan and dyed with mixed epoxy‐modified silicone oil

To enhance the color yield and improve the soft handle, hemp fabrics were treated with chitosan of molecular weight 4200 and degree of deacetylation 0.90, and then dyed using Remazol Brillant Blue R with mixed epoxy‐modified silicone oil in different volume ratios. The structural changes in hemp fibers were investigated by means of scanning electron microscope, FTIR, TG, DSC, and XRD. The properties of tensile, bending, dyeing, and color fastness for hemp fabric were also studied. The results showed that when compared with the untreated hemp fiber, the thermal performance of chitosan/silicone oil‐modified hemp fiber changed and the percent residual weight increased in the range of temperature 25–550°C. The crystal grain size decreased and the degree of crystallization increased. For chitosan/silicone oil‐treated hemp fabric, the flexural stiffness and tensile properties degraded. The maximum color yield (K/S value) was obtained when the volume ratio of dyeing liquor to silicone oil was 2 : 1. The color fastnesses to rubbing and wet scrubbing were also improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

酸性染料在纺织用甲壳胺纤维上的吸附

运用三种吸附理论模型,即Langmuir、Freundlich和Redlich-Peterson吸附模型、讨论了酸性染料在纺织用甲壳胺纤维上的吸附机理,并研究了染色温度对吸附参数的影响和硫酸钠在染色中的作用研究结果表明,Langmuir和Redlich-Peterson模型均能很好地描述酸性染料在甲壳胺纤维上的吸附性质,酸性染料以离子键的形式在甲壳胺纤维上发生吸附;酸性橙11在甲壳胺纤维上的吸附是典型的放热过程,Langmuir吸附常数KL随着染色温度的升高而降低,染浴中加入硫酸钠导致了酸性染料吸附量的降低,这意味着硫酸钠在染色中将起缓染作用     

壳聚糖及丁二酸酐酰化壳聚糖双氧水降解行为的研究

在简单均相体系下．研究了壳聚糖及丁二酸酐酰化壳聚糖在双氧水中的降解特性。采用鸟氏粘度计,利用一点法测量了降解过程中壳聚糖及丁二酸酐酰化壳聚糖的分子量,讨论了该体系下壳聚糖及丁二酸酐酰化壳聚糖的降解速率．通过红外光谱分析了双氧水对低分子量壳聚糖和低分子量丁二酸酐酰化壳聚糖结构的影响。结果表明．在该体系下·壳聚糖及丁二酸酐酰化壳聚糖的降解主要发生在反应开始后的2～3h内．此后降解产物的分子量逐渐趋于20000;相同条件下,丁二酸酐酰化壳聚糖的降解程度高于壳聚糖;红外光谱表明．采用该降解体系制备的降解产物主链结构基本没有发生变化。     

Citric acid used as a crosslinking agent for the grafting of chitosan onto woolen fabric

Modification of woolen fabrics was done by the grafting of low‐molecular‐weight deacetylated chitosan in the presence of citric acid as a crosslinking agent with the pad–dry cure method at different conditions (times and temperatures). The add‐on of chitosan and the optimum conditions were determined. The improved properties of modified wool by chitosan were evaluated with the urea bisulfite solubility test, crease recovery angle, yellowness index, and scanning electron microscopy. The dyeing properties of modified wool fabrics were studied with acid and reactive dyes. The biocidal activities of the modified and unmodified wool samples were evaluated and compared against some species of microorganisms, including Escherichia coli (Gram negative), Staphylococcus aureus (Gram positive), Candida albicans, and Aspergillus flavus. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

复合絮凝剂对染料废水的脱色作用

用羧甲基壳聚糖(CMCTS)复合聚合氯化铁(PFC)对相对分子质量较小的活性染料模拟废水进行脱色处理.结果表明,引入PFC作为助凝剂的脱色效果优于单纯使用CMCTS.采用此复合絮凝剂处理染料废水的最佳条件为pH=5,CMCTS和PFC的投加质量浓度分别为90 mg/L和2 mg/L.在此优化条件下,染料废水的脱色率可达93.8%,COD去除率达89.6%.     

Effect of low‐temperature plasma and chitosan treatment on wool dyeing with Acid Red 27

This study examines in detail the influence of low‐temperature plasma and biopolymer chitosan treatments on wool dyeability. Wool knitted fabrics were treated and characterized by whiteness and shrink‐resistance measurements. Surface modification was assessed by contact‐angle measurements of human hair fibers, which were used as a model to study the wetting properties of the treated wool knitted fabrics. The dyeing behavior was assessed from the diffusion mechanism point of view. The dyeing kinetics were measured at two different pHs (4.2 and 6.5) and three different temperatures (60, 85, and 100°C) to gain information about the contribution of the surface modification treatment to the dyeing mechanism. The exhaustion and reflectance data were compared, and the apparent diffusion coefficients were calculated. On the basis of the obtained results, a model for the dyeing mechanism of the chitosan treated wool was proposed. When treated with chitosan, the polymer sheath spread on the surface of the fibers acted as a predominant dyeing site in very short dyeing times, thus interacting with the dye and in later stages imparting the dye to the wool fiber. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2204–2214, 2005     

Effect of immobilized neutral protease on the preparation and physicochemical properties of low molecular weight chitosan and chito‐oligomers

Neutral protease was immobilized on glutaraldehyde‐pretreated N‐succinyl chitosan hydrogel beads and the biocatalyst obtained was used for the preparation of low molecular weight chitosan and chito‐oligomers with molecular weight of 1.9–23.5 kDa from commercial chitosan. Factors affecting the chitinolytic hydrolysis were described. The degradation was monitored by gel permeation chromatography. The structure of degraded chitosan was characterized by Fourier transform infrared, X‐ray diffraction and liquid chromatography‐mass spectrometry. Immobilized neutral protease showed optimal depolymerization at pH 5.7 and 50°C. The degree of deacetylation of the hydrolysates did not change compared to that of the initial chitosan. The decrease of molecular weight led to transformation of crystal structure but the chemical structures of residues were not modified. The degree of polymerization of chito‐oligomers was mainly from 3 to 8. The method allows cyclic procedures of immobilized enzyme and N‐succinyl chitosan support utilization, and is suitable for a large‐scale production of the low molecular weight chitosan and chito‐oligomers free of protein admixtures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4185–4193, 2006     

Use of chitosan to improve dyeability of DP-finished cotton (II)

Chitosan was used to improve the dyeability of DP-finished cotton. Cotton fabric was treated with a mixture of chitosan, 4,5-dihydroxy-1,3-dimethyl-2-imidazolidinone (DHDMI), and catalyst in a one-step process. To investigate the effect of molecular weight of chitosan on the dyeability of treated fabrics, six chitosan samples of different molecular weights were prepared by depolymerization with sodium nitrite; 185,300, 73,200, 59,000, 21,000, 14,000, and 3,800, respectively. Chitosan improves dye uptake of direct and acid dyes considerably, and the dye uptake increases with the increase of the molecular weight of chitosan. Reactive dye uptake increases slightly in alkaline condition as the molecular weight of chitosan decreases. Higher dye uptake is obtained in acidic condition than in alkaline condition. Chitosan treatment has no discernable effect on the colorfastness to washing, but decreases the colorfastness to wet crocking by about half a point. And chitosan affects other properties of treated fabric; lower wrinkle recovery, stiffer handle, and higher breaking strength as the molecular weight of chitosan increases. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1515–1521, 1998