【作者】 李永强；

【导师】 刘今强；

【作者基本信息】 浙江理工大学 ， 纺织工程， 2013， 博士

【摘要】 聚N-异丙基丙烯酰胺(PNIPAAm)水凝胶可感知外界温度的细微变化并产生体积相变，是生物组织领域一种理想的温敏材料。但PNIPAAm本身机械强度很差，其应用受到了很大的限制。通过接枝方法，如化学引发接枝、光引发接枝、辐射引发接枝和等离子体诱导接枝等，将其到接枝到力学性能较好的纤维基材上可望克服这一不足。其中，等离子体诱导接枝法是一种环境友好的、有效率的干式加工技术，备受研究者关注，但与其相关的一些基本问题仍有待进一步研究和明确。本文以棉织物和涤纶织物为基质，利用低压射频辉光放电等离子体和大气压辉光放电等离子体活化纤维表面，通过不同的等离子体诱导接枝过程，在织物表面接枝聚合N-异丙基丙烯酰胺，成功制备了温度响应型棉织物和涤纶织物。探明了等离子体处理参数、接枝反应参数对诱导接枝反应的影响；考察了接枝织物的温度响应性能及其影响因素，明确了接枝率与织物开关效应之间的关系；运用FESEM、SEM、FTIR、EDS、XPS、1HNMR、EPR等各种分析手段表征接枝织物表面形貌及结构，并结合等离子体发射光谱对大气压放电等离子体活性种的诊断和分析，揭示了棉织物和涤纶织物的等离子诱导接枝机制。通过单因素法分析了等离子体处理参数（包括等离子体放电功率、气体压强、气体流量、处理时间）对织物间接引发接枝率的影响。研究结果表明，采用射频辉光放电等离子体活化纤维，氧等离子体处理时间、放电功率、气体压强均与织物间接引发接枝率之间存在着密切的关系，等离子体对织物表面活化的同时，也存在着一定的刻蚀作用，而过强的刻蚀作用会削弱对织物的活化效果；控制等离子体处理条件可以获得较高的接枝率；采用APGD等离子体活化棉纤维，激励电压在90-120V范围内，通入一定量的氩气，可获得较好的辉光放电等离子体，同时控制大气压等离子体处理条件可有效地获得较高的接枝率。对直接引发接枝方式也进行了研究，对涤纶织物，相比氧等离子改性后在单体溶液中进行接枝的方法，氩等离子体共引发接枝需要更长的等离子体处理时间及更高的放电功率，方能获得较高的接枝率。探讨了单体浓度、温度、时间等因素对经等离子诱导活化的棉织物和涤纶织物与N-异丙基丙烯酰胺单体之间接枝反应影响，获得了较佳的接枝反应条件。单体用量的提高会相应的提高接枝率；反应温度以15-20℃为宜，过高的反应温度会使已接枝的温敏聚合物在织物表面发生相变收缩，限制单体的扩散，从而降低棉织物和涤纶织物的接枝率；为保证反应能彻底进行，棉织物接枝反应时间选取16h为宜，涤纶织物接枝反应时间选取8h为宜。棉织物和涤纶织物等离子体诱导接枝后的水通量和差热分析实验结果表明，和未处理织物相比，接枝织物在不同温度的水通量有明显的差异；氧等离子体和APGD等离子体诱导接枝后的棉织物在34℃附近具有明显的相转变行为；而氧等离子体诱导接枝及氩等离子体共引发接枝涤纶织物在32℃~34℃附近具有明显的相转变行为；氧等离子体诱导接枝棉织物及涤纶织物的温度响应系数随着接枝率的提高而愈加明显，但接枝涤纶织物接枝率达到某一临界值后，再继续增大反而会削弱接枝织物的开关效应。织物表面润湿性实验和接触角实验结果表明，APGD等离子体诱导接枝棉织物在低于相转变温度时织物表面表现为亲水性，在室温时水接触角为0°，高于相转变温度时织物表面表现为疏水性，在40℃时水接触角为128.3°。亚甲基蓝染色实验结果从侧面佐证了接枝涤纶织物的温度响应性能。涤纶织物的氧等离子体诱导接枝反应中，BIS用量的提高有利于提高接枝率和接枝均匀性，但过高的用量会削弱接枝织物的开关效应；过高的反应温度也会降低涤纶接枝物的温度响应系数；在一定范围内，接枝聚合过程中亲水性单体AAm的加入可以使接枝涤纶织物的相变温度增大，并且其随着AAm用量的增加而增高；水环境中盐溶液使LCST向低温方向调节，LCST随着NaCl溶液浓度增大而减小。接枝织物的红外光谱、EDS、XPS分析和电镜结果表明，经等离子体诱导接枝后，棉织物、涤纶织物表面已引入了PNIPAAm。EPR分析结果表明，经等离子体活化后的棉织物、涤纶织物表面均产生了自由基。等离子体诊断结果表明APGD等离子体中包含Ar正离子、O正离子、N正离子。在氧等离子体或APGD等离子体对棉织物活化过程中，自由基主要产生于棉纤维大分子C(2)和C(6)的羟基位置，并以此为中心发生了接枝聚合反应。氧等离子体或氩等离子体对涤纶织物的活化过程中，自由基主要产生于涤纶大分子中乙二醇链段上，并以此为中心发生了接枝聚合反应。更多还原

【Abstract】 Poly (N-isopropylacrylamide)(PNIPAAm) hydrogel can sense a very minute change in theexternal environment temperature and generates a volume phase transition, which was widelyused in the field of biological tissues. The mechanical strength of PNIPAAm itself is poor, so itsapplication has great restrictions. In order to overcome this drawback, many methods, such aschemical grafting, gamma ray radiation grafting, photo-induced grafting, low temperatureplasma grafting and so on, can be applied to graft PNIPAAm on the substrate of fiber. In thesemethods, low temperature plasma grafting is an environmentally friendly, efficient, and dryprocessing technology, which was concerned by researchers. However, some of the basic issuesrelated to the grafting by plasma-induced are yet need to be further investigated or confirmed.In this paper, the low-pressure RF glow discharge plasma and atmospheric pressure glowdischarge plasma were used to activate cotton and PET fiber surface. Thetemperature-responsive cotton fabric and polyester fabric were successfully prepared bydifferent plasma induced grafting methods. The effects of reaction conditions, such as plasmatreatment parameters, grafting reaction parameters on the grafting were investigated.Meanwhile, the temperature-responsive property of the graft fabrics and its influence factorswere investigated. The relationship between the graft ratio and switching effect of fabrics wererevealed. To reveal the grafting mechanism, the morphological changes and structure of graftedfabric were characterized through analysis methods, such as field emission scanning electronmicroscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), EDS, X-rayphotoelectron spectroscopy (XPS),1HNMR and EPR. And the active species in atmosphericpressure discharge plasma were determined by plasma emission spectroscopy.The effects of plasma treatment parameters on the graft ratio of fabrics were investigated,such as discharge time, discharge power and flow pressure. The results showed that there existsa close relationship between plasma parameters and the graft ratio. The plasma activation andetching occur simultaneously at the plasma treatment process. Strong plasma etching willweaken the activation effect of fabrics. A higher graft ratio can be obtained by controlling theplasma parameters. To obtain a higher grate ratio, a longer plasma treatment time and higher discharge power should be selected, when polyester fabrics are grafted by argon plasmainduced in one step method (plasma treatment on fabrics pre-impregnated), compared withoxygen plasma induced in two step method (plasma activation of fabric followed by soakinginto monomer solution).When APGD plasma activated cotton fibers, energizing voltage shouldbe controlled at90-120V, a certain amount of argon gas will be helpful to obtain good glowdischarge effect. Meanwhile, a higher graft ratio can be obtained by controlling the atmosphericpressure plasma treatment conditions.The effects of monomer solution concentration, reaction temperature and time on thecotton and PET fabrics grafting using NIPAAm monomers were discussed and optimumgrafting reaction conditions were obtained. The increase in the monomer concentration leads tothe increase in the graft ratio. Increasing reaction temperature is not helpful to get a higher graftratio. At a higher temperature, the grafted polymers shrink on the surfaces of fabrics andmonomer diffusivity is restricted significantly. The reaction temperature should be controlled at15-20℃. In order to ensure the complete reaction, grafting reaction time of cotton fabricsshould be selected for16hours, and8h is an appropriate reaction time for polyester fabrics.After grafting, a significant difference on the water flux was observed at differenttemperatures as compared to the control fabrics. Grafted cotton fabric show obvious phasetransition endotherm at34℃, and grafted polyester fabric show obvious phase transitionendotherm at32~34℃. In a certain range, the switch effect of cotton and polyester fabric isgetting stronger as the graft ration increases, after reaching a certain threshold, increasing graftration will weaken switch effect of polyester fabrics. According to wetting experiments andwater contact angle tests results，the surface of grafted cotton fabric by APGD plasma inducedis hydrophilic with a water contact angle of0°below LCST at room temperature, andhydrophobic with a water contact angle of128.3°above LCST at40℃. Methylene blue dyeingresults revealed yet the temperature-responsive property of the grafted polyester fabrics.The increasing of BIS concentration benefits to getting a higher graft ratio and improvingthe grafting uniformity, but further increase will weaken the switch effect of the graftedpolyester fabrics. The reaction temperature which is too high will weakentemperature-responsive coefficient of the grafted polyester fabrics. In a certain range, the morethe amounts of AAm are added in the grafting reaction, the higher the LCST increases. And with the concentration of NaCl solution increasing, the LCST decreases.FTIR and XPS spectra of grafted fabrics by plasma-induced indicated that the NIPAAmmonomers were grafted from cotton and PET fabrics surfaces, which was further confirmed bythe EDS test and SEM results. EPR spectra of plasma-treated fabrics showed that the freeradicals have been generated on cotton and polyester fabric surfaces after plasma treatment.Plasma diagnostic results show that there exists Ar positive ion, O positive ion and N positiveions in the APGD plasma. When the oxygen plasma or APGD plasma activated cotton fabrics,free radicals are generated in the hydroxyl groups of the C (2) and C (6) atom of the cotton fibermacromolecules. And the grafting polymerization take place at this position. When the oxygenplasma and argon plasma activated polyester fabrics, the free radicals were generated only onthe EG chain segments of the polyester macromolecules, and then chain propagation grew atthat points.更多还原