【作者】 史吉华；

【导师】 阎克路；

【作者基本信息】 东华大学 ， 纺织化学与染整工程， 2014， 博士

【摘要】 羊毛是一种具有鳞片层结构的天然蛋白质纤维,它富有弹性,具有良好的吸湿性和保暖性。但是羊毛本身特有的鳞片层会产生定向摩擦效应,易产生毡缩,极大影响其服用性能。传统的羊毛防毡缩整理中常使用氯气或释氯剂,处理过程中产生的AOX(absorbable organic halogen)会对环境造成严重污染。水性聚氨酯(PU)是无氯防毡缩常用整理剂,但要获得良好的防毡缩效果使用量很大,整理后织物变硬,羊毛手感变差。采用生物质材料壳聚糖来增强水性聚氨酯,可以较大幅度降低羊毛防毡缩剂的使用量,使得PU在羊毛纤维表面形成的膜变薄,这不仅可改善整理后羊毛的手感,大量节约整理剂原料；而且可提高毛织物的生物可降解性。另外,我国作为羊毛制品生产大国,每年产生大量的废弃羊毛,从废弃羊毛中提取羊毛角蛋白,将其应用在羊毛织物的防毡缩整理中,可使废弃羊毛这一宝贵的蛋白资源得到合理有效的利用。因此,本文研究壳聚糖改性聚氨酯的制备及其羊毛防毡缩整理工艺、以及废弃羊毛中提取角蛋白用于羊毛防毡缩工艺。同时,对壳聚糖改性聚氨酯复配液所成的膜及角蛋白与壳聚糖复合生物膜的相关性能进行探索,为今后新工艺的产业化提供理论支撑。第一部分,本文研究壳聚糖改性聚氨酯的制备及其在羊毛防毡缩整理应用工艺。研究发现,壳聚糖分子量的大小对增强效果有较大影响,这在文献中鲜有报道。本文筛选和制备一种合适分子量范围的壳聚糖,在实际应用中可与聚氨酯以任意比例混合,可以现配现用,为工业化应用奠定基础。首先,本文采用H2O2-微波酸性复合降解工艺对高分子量的壳聚糖进行降解,得到11种不同分子量范围的壳聚糖,探讨了过氧化氢用量和微波处理时间对降解产物粘均分子量、产率、稳定性等的影响,并通过红外测试对降解产物进行结构分析。随着微波时间和过氧化氢用量的增加,壳聚糖分子量逐渐降低,颜色逐渐加深,产率也逐渐下降。其次,将所得11种不同分子量的壳聚糖与聚氨酯以一定比例复配,然后进行羊毛防毡缩整理,重点研究了壳聚糖的分子量、聚氨酯用量、壳聚糖与聚氨酯的质量百分比等对复配液的稳定性、均匀性及防毡缩效果的影响。通过对羊毛织物的毡缩率、力学性能等的测试,确定羊毛防毡缩整理的最佳工艺条件。结果表明,粘均分子量为3×104D的降解壳聚糖与60g/L的聚氨酯复配成质量百分比为4%的复配液,其防毡缩效果最理想,面积毡缩率达0.1%,达到ISO6330、IWS TM NO.31防毡缩技术标准和市场的要求。少量粘均分子量为3×104D的壳聚糖通过复配的形式与聚氨酯进行共混,大大提高了复配液的均匀性及稳定性,并且可以现配现用,适用于工厂大规模生产。与不加壳聚糖的聚氨酯整理羊毛织物的工艺相比,壳聚糖的加入使聚氨酯的用量降低了45%,同时改善了织物手感、增强了织物的强力。第二部分：较系统研究壳聚糖/聚氨酯复合膜的性能。利用粘均分子量为3×104D的改性壳聚糖与60g/L的聚氨酯形成的复配液进行成膜性实验。动态热机械分析仪(DMA)测试结果表明,壳聚糖的加入使复合膜的拉伸强力提高40%、储存模量提高6%,这说明壳聚糖的加入对聚氨酯的增强效果明显。此外,壳聚糖的加入使得复合膜的玻璃化转变温度从-52℃升高到-45℃,这主要是壳聚糖与聚氨酯的软段发生相互作用,从而破坏聚氨酯软段与硬段之间的相互作用,导致微相分离程度有所加剧所致。热力学测试表明,壳聚糖的加入使得聚氨酯的热稳定性有所改善。红外光谱(FTIR)的测试结果说明壳聚糖与聚氨酯之间存在一定的化学交联。另外,通过生物降解性测试结果发现壳聚糖的加入可以有效改善聚氨酯的生物降解性,使其强力在水降解条件下降低65.7%,酶降解条件下降低70.7%,改性聚氨酯膜表面出现凹槽和裂痕。本文第三部分,研究羊毛角蛋白的羊毛防毡缩工艺。首先系统地研究了生物酶溶解羊毛提取角蛋白技术,通过考察处理温度、处理时间、处理浴pH值和酶用量等条件对羊毛溶解率的影响,筛选出提取羊毛角蛋白的最佳工艺条件。借助SDS-凝胶电泳、傅里叶变换衰减全反射红外光谱、广角X射线衍射和热重分析等测试手段分析了酶法提取角蛋白的结构与性能,并与熔融尿素法和传统还原法所得角蛋白进行对比,同时对羊毛溶解机理进行了初步探讨。研究结果表明,采用蛋白酶法的羊毛溶解率和角蛋白产率分别高达90.1%和87.6%,角蛋白分子结构中二硫键部分断裂,其分子量<2kD,呈多肽形式,结晶度为45.2%,其热稳定性逊于熔融尿素法和氧化-还原法产品。其次还对羊毛角蛋白溶液用于羊毛织物的防毡缩整理亦进行了探讨。研究了不同工艺提取的角蛋白分子对羊毛防毡缩效果的影响,分子量较大对羊毛防毡缩效果稍好。并首次对比纯角蛋白、粗角蛋白、纯还原剂、角蛋白/还原剂、预处理-角蛋白/还原剂等不同工艺对织物防毡缩效果及物理机械性能的影响,优化羊毛织物防毡缩整理工艺。结果显示,纯角蛋白对羊毛防毡缩性影响不大,需要与还原剂协同作用才有效果；追加还原剂和亲水化预处理均能促进角蛋白对织物的防毡缩性,追加还原剂可以还原羊毛织物中的二硫键,产生较多的巯基-SH,可以与角蛋白中的巯基-SH进行反应生成新的二硫键,增强角蛋白与羊毛之间的结合,增强其耐洗性,亲水化预处理可以增加羊毛的亲水性,使角蛋白与羊毛更容易接触；优化工艺条件整理后羊毛织物的毡缩率由11.1%降至1.2%,达到国际羊毛局机可洗标准,且织物强力损失小,手感柔软,无泛黄现象。本文第四部分,研究角蛋白—壳聚糖复合膜的制备及其力学性能、热稳定性、亲水性、抗菌性等。角蛋白具有很好的亲水性,所成膜较脆,影响其应用性能。这也是其在羊毛防毡缩中效果不佳的原因。本研究通过将壳聚糖与角蛋白在活化剂兼交联剂EDC(碳二亚胺)的作用下进行反应制备具有一定机械强度的复合生物膜。通过傅立叶红外光谱、X射线衍射图谱、热重分析等测试技术对复合生物膜的性能进行表征和分析。研究表明EDC的加入使得壳聚糖与角蛋白之间发生化学交联,壳聚糖与角蛋白质量比为7：3时,热稳定性最好,分子排列最规整。对生物膜进行接触角测试发现,随着壳聚糖含量的增加、复合生物膜的亲水性逐渐降低。对生物膜进行强力测试发现,随着壳聚糖含量的增加,其断裂强度总体增大,当壳聚糖与角蛋白质量比为7：3时,强力最好。更多还原

【Abstract】 Wool is a kind of natural protein fiber with scale layer structure, whichhas good hydroscopicity, warmth-retention and elastic properties. However, the characteristic scale layer with directional friction effects can easily generatefelting and would affect their performance greatly. Chlorideand its derivatives were used for wool anti-felting finishing in traditional process.However, AOX (absorbable organic halogen) was produced during this process and polluted the environment seriously. Waterborne polyurethane, a kind of free chlorine anti-felting finishing agent, could cover the scales of wool fiber due to the formation of a thin film. The huge amount of waterborne polyurethane is applied to get better anti-felting, which results in the hardening of fabric and bad handle feeling.Using biomass material chitosan to enhance waterborne polyurethane will reduce the usage of wool felting agent, which leads to the formation of a thinner film. As a result, this could not only improve the handle feeling, save the cost, but also improve the biodegradability of finished wool fabric. In addition, huge amount of wool generated in China are disposed as waste. Wool keratinextracting from waste wool was used as agent for anti-felting application. The valuable protein from the wasted wool could be more reasonable and effective use by this way.Therefore, the subjectstudied on preparation of polyurethane which was modified by chitosan and anti-felting finishing processes of wool fabric treated by modified polyurethane, as well as the anti-felting finishing processes of wool fabric treated by keratin extracted from the waste wool. At the same time, the related properties of the chitosan/polyurethane composite films and chitosan/keratin composite films were studied. This provides theoretical support for the industrialization of new technology in the future.In the first part, the anti-felting finishing technology of wool fabric with polyrehane modified by chitosan was studied. There is nearly no report about the effect of the size of molecular wight of chitosan on enhancement of polyurethane. So an appropriate molecular weight within a certain scope of chitosan was seleted and prepared. And the chitosan could be mixed with polyurethane in any proportion in practice. And the mixture could be prepared immediatelywhen needed. This would lay the foundation for industrialized application.Firstly, the chitosan with high molecular weight was hydrolyzed with H2O2under mocrowave irradiation in anticipation of obtaining11kinds of chitosan with different molecular weights. The effects of concentrations of H2O2and irradiation time were investigated by the single factor test. The structure of the product was confirmed by FTIR spectrum analysis. The changes in the molecular weights of the hydrolyzed chitosan are strongly dependent on the reaction time and the concentration of H2O2.Secondly, eleven kinds of the hydrolyzed chitosan were mixed with polyurethanein in certain proportion. Then they were used for antifelting finishing of wool fabrics. The effects of the chitosan molecular weights, dosage of polyurethane, and the quality percentage of chitosan on the stability, uniformity and anti-felting of the mixed solutions were mainly researched. The optimum process of antifelting finishing was determined by the results of shrinkage area and mechanical properties tests. The results showed that the area shrinkage was0.3%,which meets the requirements of factory production of common standards when the proportion of chitosan with molecular wight of3X104D was4%in proportion of polyurethane and the concentration of polyurethane was60g/L.A small amount of low molecular weight of modified chitosan was blended with polyurethane to improvethe uniformity and stability of the compound solution greatly. The solution could be prepared when needed. This could be suitable for industrial application. The amount of modified polyurethane was reduced by45%. Meanwhile, the handle feeling of the processed fabric was improved and the strenght of the fabric was enhanced.The second part was about the systematic research of chitosan/pu composite membrane performance. The polyurethane modified by hydrolyzed chitosan with viscosity molecular wight3×104D forms membrane easily.The results of DMA tests showed that the tensile strength of the modified polyurethaneincreases by40%. The chitosan effectively enhanced the polyurethane. In addition, the chitosan mainly interacted with the soft segment of the polyurethane, and undermined the interaction between the soft segment and the hard segment of the polyurethane. This could induce the increase of the micro phase separation degree and the glass transition temperature (-52℃to-45℃). Thermodynamic test results showed that the modified polyurethane has better thermal stability. FTIR test results showed that the chemical crosslinking existed between the chitosan and polyurethane.The biodegradability test results found that the addition of chitosan could effectively improve the biodegradability of polyurethane and could make its strength to decrease respectively65.7%and70.7%under the conditions of water degradation and enzyme degradation conditions. The modified polyurethane membrane surfaces appeared grooves and cracks.The third part was about wool keratin processes for wool fabric shrinkproof.Firstly, the technique of enzyme extracted wool keratin was systematically studied. Theprocessing temperature, processing time, processing bath pH value and enzyme dosage were investigated by the single factor test.And then the optimum process was selected. The analysis and comparision of the structure and properties of keratins extracted respectively by protease, molten urea and oxidation-reduction method through SDS-PAGE、ATR-FTIR, WAXD, TG and DTG tests. The dissolution mechanisms of the wool were also explored. The tests results showed that the dissolution rate and production rate of keratin protein extracted by enzymatic method were90.1%and90.1%respectively. The disulfide bonds of keratin molecular structure fracture partially ruptured and the molecular weight of the keratin was less than2kD. The keratin was in the form of apolypeptide and the crystallinity was45.22%. Its thermal stability is inferior to those extracted by the molten urea method and oxidation-reduction method.Secondly, the wool keratin solutions were applied on woolen fabric directly.The processes of different wool keratin applied on antifelting finishing of wool fabrics were discussed. Keratin with large molecular has better anti-felting effect. The effects of different processes of pure keratin, pure reductant, rough keratin, keratin/reductant, pretreatment-keratin/reductant on antifelting effect and mechanical properties were compared. Results showed that Better antifelting effect was obtained when the keratin and the reductant acted synergistically. Additional reductant and hydration pretreatment could promote the anti-felting effect. The reductant could retain the-SH of the keratin and reduct the disulfide bond in wool fabric to produce more-SH. The-SH of the keratin and wool fabric restructured to generate new disulfide bond to strengthen the combination of the keratin and wool and enhance their resistance of washing. The hydrophilization pretreatment could increase the hydrophilicity of wool and make the keratin easier to contact with the wool fabrics.The shinkage area of the processed wool fabric under the optimum condition was decreased from11.1%to1.2%. This reached the IWS standard. And the strength loss of the processed fabric was small and the handle feeling of the fabric was soft. There was no yellowing phenomenon.The fourth part was about the preparation and characterization of the keratin-chitosan composite membranes. Keratin has good hydrophilicity. Keratin film was brittle, whichaffects its application performance and is the reason for its bad antifelting effect of the wool fabric. And the chitosan and keratin reacted in the presence of the EDC to form the composite biofilm which had certain mechanical strength.The characterization and analysis of the keratin-chitosan composite biofilms were tested by Fourier transform infrared spectroscopy, X-ray diffraction spectrum, thermogravimetric analysisand so on. The results of above tests showed that chitosan and keratincrosslinked in the presence of EDC. When chitosan and keratin quality ratio was7:3, the bio-composite film has the best thermal stability and the most regular molecular arrangement.The contact angle tests found that the hydrophilicity of biological composite membranes gradually decreased with the increase of the content of chitosan. Strength test results showed that the breaking stress generally increase with the increase of the content of the chitosan. When chitosan and keratin quality ratio was7:3, the strength was the best.更多还原