【作者】 孙世元；

【导师】 邱夷平；

【作者基本信息】 东华大学 ， 纺织材料与纺织品设计， 2013， 博士

【摘要】 禁用聚乙烯醇(PVA)等环境污染性浆料,利用淀粉类绿色浆料对棉纱进行上浆是生态浆纱技术的重要研究方向。但是淀粉类浆料单独使用时往往会带来浆膜脆硬、纱线不耐磨、织造时容易断头等问题,极大地影响了织造效率。而棉纤维由于其表面有一层拒水表皮层,使得棉纱不易润湿,浆液向纱线内部渗透困难。并且,随着现代高速浆纱技术的发展,纱线在浆槽内浸浆时间大大缩短,也对浆料的渗透和被覆效果提出了挑战。为了克服上述浆料、棉纤维和高速浆纱技术自身特性对棉纱浆纱带来的不利影响,实现利用淀粉类绿色浆料对棉纱(尤其是高支棉纱)进行生态浆纱的目标,本课题重点研究了利用氦气／氧气(He/02)常压等离子体(APP)对棉纱进行预处理,以提高棉纤维表面润湿性和对浆料的粘结性,然后使用含有磷酸酯淀粉和甘油组分的绿色浆料对APP预处理过的纱线进行上浆的生态浆纱技术(Eco-friendly Sizing Technology, EFST)。课题的主要研究内容包括：APP预处理改善原棉纤维表面润湿性和对浆液粘结性的基础理论、棉纤维回潮率(含水率)对APP处理棉纱效果的影响规律、基于APP预处理和绿色浆料使用的EFST生态浆纱技术以及APP浆前预处理对织物前处理及染色性能的影响等。首先,本课题研究了APP预处理工艺条件对棉纤维润湿性能的影响。APP不但可以轰击棉纤维表面产生物理溅射和化学刻蚀作用从而破坏纤维的疏水表皮层,而且同时在纤维表面生成自由基,引发等离子体植入官能团反应,在纤维表面植入羟基(C-OH)、羧基(COOH)和羰基(C=O)等极性基团,显著地提高其表面能,增强其润湿性,使其润湿时间从几个小时减小到0.8秒甚至更小,表面接触角从140°左右降低到0°。棉纤维表面粗糙程度和润湿性随着APP处理条件的改变而变化。当其它条件不变,等离子体喷头到纤维之间的距离(Jet to the Substrate Distance, JTSD)从2毫米减小到0.5毫米时,纤维表面粗糙程度逐渐变大；棉纤维润湿时间随着APP处理时间和O2流量的增加而减小,随着JTSD的增大而提高。APP处理后棉织物的润湿性在24小时内没有显著的变化,这主要因为原棉纤维的拒水表皮层已经受到等离子体的刻蚀、氧化而被破坏,表面被植入大量的亲水性基团所造成的。其次,本课题研究了APP预处理条件对棉纱与磷酸酯淀粉浆料之间的浆液粘附力及浆纱断裂伸长率的影响。研究结果表明,棉纱浆液粘附力和浆纱断裂伸长率的大小受棉纤维表面粗糙度和润湿性能的重要影响,棉纤维表面越粗糙,润湿性能越好,浆液粘附力和浆纱断裂伸长率越大。这是因为APP对纤维表面的粗糙化改性不但能赋予其“机械锁合效应”,增强浆料对纤维的抱合力,而且还能够增加浆料和纤维表面的有效接触面积,在它们之间产生更多的范德华力；纤维表面引入的极性基团如羟基、羧基和羰基,不但使浆料更容易渗入到纱线内层,增加浆料和纤维之间的接触面积,而且可与浆料大分子形成氢键结合,进一步提高它们之间的结合力,进而提高浆液粘附力和上浆率。棉纤维表面粗糙度随着APP处理时间以及O2流量的增大先增大而后略有降低,随着JTSD的减小而增大；其润湿能力随着APP处理时间的延长而逐渐提高。在上述规律的综合影响下,棉粗纱的浆液粘附力和浆纱断裂伸长率随着APP处理时间和O2流量的增加呈现先升后降的趋势,随着JTSD减小呈现变大的趋势。在优化的APP处理条件下,棉粗纱的浆液粘附力和断裂伸长率可分别提高59%和36%。APP预处理能有效糙化棉纤维表面,提高棉纱的润湿能力、浆液渗透能力、浆液粘附力以及浆纱断裂伸长率。本课题还重点研究了不同回潮率(含水率)对棉纤维受APP处理后其润湿性和浆液粘结性能的影响。结果显示,当棉纤维回潮率较小(0.5%)时,其等离子体表面刻蚀效果较好,在纤维表面出现了大量的近似圆形的、粒径大约为0.5微米左右的微粒；XPS分析证实更多的极性基团如羟基、羧基和羰基被引入到纤维表面,从而使棉纱具有更好的润湿性能、浆液渗透性和更高的浆液粘附力,浆液沿其横截面圆周向纱线内部渗透更均匀。当回潮率(含水率)较大(9.3%、26.4%)时,由于棉纤维拒水表皮层的存在,其表面存在的大量水分消耗了等离子体粒子的能量,从而使得APP处理效果变差,导致棉纤维的刻蚀程度、棉纱的润湿性能、浆液渗透性和浆液粘附力变小,浆液在棉纱受APP处理的一侧渗透较深,沿圆周向里渗透不均匀。在以上理论研究的基础上,本课题设计了一种生态浆纱工艺,即先利用APP预处理技术提高棉纤维的润湿性和其与浆液的粘附力,然后利用含有磷酸酯淀粉和甘油组分的绿色浆料对棉纱上浆。研究结果表明,与常规的使用PVA1799和磷酸酯淀粉上浆的传统浆纱技术(Traditional Sizing Technology,TST)相比,EFST生态浆纱技术能够赋予高支棉纱更好的浆纱质量,如显著提高的上浆率、浆纱断裂强度、浆纱断裂伸长率、耐磨次数以及更为有效的浆纱毛羽抑制率。与典型的使用30%PVA1799和70%磷酸酯淀粉的配方浆料上浆的TST传统浆纱技术相比,EFST生态浆纱技术可以使浆纱上浆率、浆纱断裂强度、浆纱断裂伸长率、耐磨次数分别提高19.4%、5.3%、3.4%和169.2%,使1毫米毛羽指数值降低59.3%。APP预处理可以使各浆纱质量指标得到明显改善,绿色浆料配方中的甘油组分能够有效贴服毛羽,提高浆纱耐磨次数和上浆率。NaOH退浆实验表明,EFST生态浆纱技术对退浆效果没有不利影响,反而会提高浆纱织物的润湿性和渗透性。最后,本课题利用两种前处理工艺,即使用淀粉酶INVAZYME(?) ADC退浆、精练酶KDN301精练、H202漂白的绿色前处理工艺和使用NaOH退浆、精练剂204精练、H202漂白的传统前处理工艺,来研究浆前APP预处理的生态浆纱技术对织物的前处理效果和染色性能的影响。实验结果表明,浆前APP预处理试样与非预处理试样相比,具有更好的前处理效果和染色性能,其浆料、果胶、蜡质及其它杂质去除更为有效、彻底；同样处理条件下得到的棉织物具有较高的失重率、润湿能力、白度值、上染速率、最终上染率以及较高的表观颜色深度K/S值；各试样匀染性指数RUI介于0.2和0.49之间,表明都具有较好的匀染性；干、湿耐摩擦色牢度分别为3～4级、2～3级,未发现APP预处理对匀染性和摩擦色牢度的明显影响。研究还发现,浆前APP预处理的试样使用常规前处理工艺处理时,即使省去精练过程,其前处理效果和染色性能、染色质量能达到未APP预处理试样经过NaOH退浆、精练剂精练、H202漂白全部过程后的水平；当使用绿色前处理工艺处理时,其前处理效果和染色性能、染色质量等也能达到未预处理试样经过退浆、精练、漂白传统工艺前处理后的水平。这充分说明,使用绿色和传统两种前处理工艺都能得到较好的前处理效果；APP浆前预处理能明显提高织物的前处理效果和染色性能；在工艺条件合理的情况下,能省却精练工序而不影响整体的前处理效果和染色性能、染色质量。更多还原

【Abstract】 A lot of polyvinyl alcohol (PVA) has been discharged to the natural environment due to the high cost of recycling, which has caused great pollution because of its poor biodegradability in natural conditions. The biodegradability of polyacrylic acid sizes depends on their macromolecule structures and varies a lot. Although the BOD5/CODcr values of most polyacrylic acid sizes are less than0.25which is lower than that of PVA, polyacrylic acid sizes are difficult to degrade in natural environment. So, PVA and other sizes which could lead to environment contamination have been facing prohibition in recent years. The annual symposium for size and sizing technology in China has advocated usage of green sizes, energy saving and application of eco-friendly sizing technology for five years in a row.Starch size and its modifications are one of the most promising green sizes and they are biodegradable and abundantly available. They are often used in combination with PVA because of their poor fluidity and unstable viscosity. Some problems, such as brittleness and stiffness of size films and poor sizing properties will be encountered if starch size and its modifications are used alone, which severely affected the subsequent weaving process. Raw cotton fiber is hydrophobic due to the existence of its surface cuticle layer mainly composed of pectin and waxes, which brings a lot of difficulties for the wetting process of cotton yarn and the permeability of size to the yarn. Furthermore, the sizing time in the size box is greatly reduced to1-2sec with the development of high-speed sizing technology, which challenges the permeability and coverage effect of the size to the yarn.He/O2atmospheric pressure plasma (APP) assisted eco-friendly sizing technology (EFST) of cotton yarn has been developed in this study to consume the disadvantages of starch sizes, raw cotton fiber and the high-speed sizing technology aiming to size raw cotton yarn, especially high count yarn, with starch sizes. The EFST employs APP pretreatment of the yarn in combination with green size recipes including components of glycerol and phosphate modified starch (PM-Starch) during sizing. The yarn’s wettability, the sizing adhesion strength of cotton yarn (SAS) as well as the influence of moisture regain (MR) on them under APP treatment has been studied in this paper. The EFST and its effect on desizing, scouring, bleaching and dyeing properties of knitted cotton fabric were studied as well.Firstly, how He/O2APP pretreatment influences the wettability of raw cotton fiber was studied. He/O2APP pretreatment can dramatically improve the hydrophilicity of cotton fiber by physical bombardment and chemical etching of its hydrophobic surface. And therefore, chemical reactions triggered by radicals introduce large quantities of functional groups including C-OH, COOH and C=O to the fiber surface, which makes the surface free energy fundamentally promoted leading to a drop of Water Contact Angle (WCA) from140°to0°and Water Adsorption Time (WAT) from a few hours to only0.8sec or much less. The surface roughness and wettability of the fiber vary with APP treatment conditions including treatment duration, the O2flux and Jet to the Substrate Distance (JTSD). The surface roughness grows increasingly with the decrease of JTSD from2to0.5mm. WAT of the fiber goes down with the rise of treatment duration and O2flux, while it goes up with the increase of JTSD. There is no apparent aging effect for the wettability of cotton fiber after APP treatment because the cuticle layer of the fiber has been severely spoiled due to plasma etching, oxidation and introduction of functional groups.Secondly, the influence of He/O2APP pretreatment on SAS between cotton yarn and PM-Starch and the breaking strength of the sized yarn was investigated in this study. Results show that the surface roughness and wettability play important roles on SAS and breaking strength of sized cotton yarn, namely, they rise with the raising of surface roughness and wettability. One of the probable reasons is the "mechanical interlocking effect" induced by roughness modification which increases the cohesion force of size to fiber and van der waals’ force between them. The other is that the introduction of functional groups such as C-OH、C=O and O-C=O to the fiber surface not only facilitate the permeating of the size into the yarn but also form some intermolecular hydrogen bonds between the fiber and the size. Both of them contribute to the improvement of SAS between the fiber and the size due to increased contact area and hydrogen bond forces between the fiber and the size. The surface roughness increases first and then decreases with the prolongation of treatment duration and rise of O2flux, while improves as JTSD goes down. The wettability of the fiber rises increasingly with the rise of treatment time. SAS and breaking strength of the sized yarn increase first and then decrease with the prolongation of treatment duration and rise of O2flux, and improve with the decrease of JTSD showing the same regularity with the change of surface roughness. With the optimized APP treatment conditions, SAS and breaking strength of the sized yarn could be greatly improved by59%and36%, respectively. In conclusion, He/O2APP pretreatment of the yarn can effectively roughen fiber surface and improve the wettability, size permeability, SAS and breaking strength of the sized yarn.Emphasis has also been laid on the influence of MR of cotton fiber on its wettability and sizing adhesion in this paper. Results demonstrated that the etching effect of APP on fiber surface is better when MR is lower, such as0.5%, and a large number of nearly round-shaped particles with diameters of around0.5to1μm appeared on the fiber surface after the plasma treatment. A moderate etching effect was found on the fiber surface of Sample with a higher MR of9.3%. It can be concluded that cotton fibers with lower MRs can be more efficiently etched than those with higher MRs. X-ray photoelectron spectroscopy (XPS) result showed that more functional groups including C-OH、O-C-O/C=O and O-C=O have been introduced to the fiber surface resulting in better wettability, size permeability and SAS of the yarn, and a more uniform size permeation into the yarn from yam surface was obtained at the same time. When MR is higher, such as9.3%and26.4%, a lot of water will exist on the fiber surface and consume large quantities of plasma energy, which weakens the APP treatment effect leading to poor wettability, size permeability and SAS of the yarn. Besides, the size permeation prefers to the APP treated side of the yarn showing a poor uniformity.On the basis of above research, the EFST has been proposed and put into practice. APP pretreatment of the yarn was conducted first and then the green size with PM-Starch and glycerol ingredients was used to size the yam. Results show that EFST can impart the yarn better sizing properties, such as improved size-pick-up, breaking strength, breaking elongation, abrasion resistance time and more effective reduction of yarn hairs, compared with TST. In comparison with typical TST using the sizing recipe with30%PVA1799and70%PM-Starch, the optimized EFST can impart the yarn an increase of19.4%,5.3%,3.4%and169.2%for the size-pick-up, breaking strength, breaking elongation and the abrasion resistance time, respectively, and a reduction of59.3%for the yarn hairiness index value at level1. The sizing properties can be obviously improved by the atmospheric pressure plasma treatment which can roughen the fiber surface, etch away the hydrophobic cuticle layer and introduce polar groups. The glycerol in the green sizing recipes can effectively reduce the yarn hairiness and increase size-pick-up and abrasion resistance. The eco-friendly sizing technology has no observable negative influence on desizing of cotton fabrics. Furthermore, a better water diffusion in the fabric can be achieved because of the improved hydrophilicity by the plasma treatment.In the end, the influence of APP treatment before sizing on pretreatment and dyeing properties of knitted cotton fabric has been ascertained through green and traditional pretreatment technologies. INVAZYME(?) ADC enzyme desizing, KDN301enzyme scouring and H2O2bleaching were employed in the green pretreatment technology, while NaOH desizing, scouring agent204for scouring, H2O2bleaching were adopted in the traditional pretreatment technology. Results illustrate that Size, pectins, cotton waxes and other natural contaminations can be more efficiently removed from APP pretreated fabrics than not APP treated ones, and consequently higher weight loss, wettability, whiteness, dying rate, final dye up-take and K/S value will be obtained. APP pretreated fabrics have better desizing, scouring, bleaching and dyeing performances than not APP treated ones, and dyeing properties such as color levelness and dry rubbing fastness of dyed fabric are not apparently affected by APP. The color difference shows almost the same regularity with the changing of K/S values and relative unlevelness index (RUI) values are between0.2and0.49showing good levelling property, which means APP treatment has no apparent effect on dyeing properties. The possible reasons for APP pretreated fabrics getting better pretreatment and dyeing performances are as follows:one is the removal of hydrophobic cuticle layer, the other is the increase of functional groups by APP oxidation. Both contribute to the improvement of hydrophilicity of sized fabric leading to quick removal of size, residual cotton waxes and pectins under the action of pretreatment reagents, which improves desizing, scouring and bleaching effect.APP pretreated fabrics can obtain almost the same pretreatment and dyeing performances by using the traditional technology with scouring process excluded. When the green pretreatment technology with the use of INVAZYME(?) ADC starch enzyme and scouring enzyme is applied to the APP pretreated fabrics, almost the same pretreatment and dyeing performances with that of the traditional technology can be attained. It can be concluded that both green and traditional pretreatment technology can provide the sized fabric with a good pretreatment effect and APP pretreatment can substantially improve pretreatment effects, dyeing performances and dyeing properties. With the application of APP treatment and optimized pretreatment technology, the scouring process can be omitted to save energy and reagents, not affecting the pretreatment effects, dyeing performances and dyeing properties.更多还原