最新专利

<正>改善了耐洗性的含抗菌聚酯产品的制造方法本发明涉及利用壳聚糖及壳聚糖-金属络合物的含抗菌聚酯的产品,通过壳聚糖类物质与聚酯的共价结合改善了该产品的耐洗性。本发明还涉及制造所述产品的方法。(CN 1784520A,2006-06-07)一种制备高性能聚乙烯醇纤维的方法本发明涉及一种采用熔融纺丝制备高性能聚乙烯醇纤维的方法。采用由含氮化合物、亲水性辅助添加剂和水组成的复合改性剂与聚乙烯醇进行分子间氢键复合,制备改性聚乙烯醇；熔融纺丝制备截面为圆形或异形、结构均匀的聚乙烯醇初生纤维；聚乙烯醇初生纤维通过多级拉伸、干燥、热定型制备高性能聚乙烯醇纤维。本发明通过分子间氢键复合实现了聚乙烯醇的熔融纺丝和高倍拉伸,从通用级聚乙烯醇制备力学性能优良的聚乙烯醇纤维,不需传统湿法纺丝方法中凝固浴等相关复杂工序,工艺简单、经济、环保,易于实现工业化生产。(CN 1786302A,2006-06-14)     

聚乙烯醇高分子表面活性剂的研究

通过本体聚合方法合成了高分子量的聚醋酸乙烯酯，由其水解得到的聚乙烯醇与苯甲酰氯进行接枝反应得到改性的聚乙烯醇．对改性的聚乙烯醇进行的一系列结构与性能研究表明：它具有较高的表面活性，存在单分子和多分子胶束，其特性粘数比未改性的聚乙烯醇高，是一种新型的非离子表面活性剂．     

胶水级聚乙烯醇缩甲醛的实验条件探索

聚乙烯醇(PVA)是一种无色、无毒、无腐蚀性的水溶性有机高分子聚合物,但该产品在耐水性、黏度和抗冻性等方面尚不能满足要求,人们采用缩醛改性、酯化改性、内酯改性、疏水改性等方法对其性能进行优化,其中缩醛改性应工艺简单、改性效果明显而得到广泛应用。本文以聚乙烯醇缩甲醛实验制备为重点,探讨了水和聚乙烯醇的配比、甲醛用量、反应时间、反应温度、p H值等因素对胶粘剂性能的影响。在此基础上,提出了改进工艺的最佳条件,制备了聚乙烯醇缩甲醛改性胶液,使其在黏度、耐水性等性能方面有显著提高,并降低了胶液的甲醛含量。     

疏水物改性聚乙烯醇缔合型增稠剂

将十六醇引入聚乙烯醇大分子中，合成了疏水缔合型增稠剂。流变性研究结果表明，改性的聚乙烯醇分子间存在相互缔合作用。５ ％ 改性聚乙烯醇溶液的粘度可达１６－０ Ｐａ·ｓ ，较未改性的聚乙烯醇增稠效果更好，耐盐性更佳     

聚乙烯醇的熔融加工工艺与性能研究

本文主要研究了聚乙烯醇的熔融加工工艺及其性能。聚乙烯醇是一种生物可降解高分子材料,但是聚乙烯醇分子链中含有大量的羟基,容易在分子内或分子间形成大量的氢键,熔融温度高于分解温度,熔融加工困难。本实验通过甘油和芥酸酰胺复配作为增塑剂,降低聚乙烯醇的熔点,使其能够在适合的加工工艺下熔融加工。并以轻质碳酸钙为填料,对聚乙烯醇进行填充改性。实验表明,在增塑剂为20份,轻质碳酸钙为30份时,拉伸强度得到明显提高。     

聚乙烯醇热塑改性研究进展

聚乙烯醇具有良好的使用性能和环境友好性能,是公认的绿色可降解材料。但聚乙烯醇分子结构高度规整,分子内和分子间存在强氢键作用,导致其熔点和热分解温度相近,热加工窗口窄,难以热塑加工成型,应用领域受限。本文以聚乙烯醇成品前后两个阶段为重点,系统介绍了近些年聚乙烯醇热塑改性的方法。文中指出,聚乙烯醇成品前期改性为共聚改性（改性单体为乙烯类单体、丙烯酸酯类单体和其他单体）以及调控聚合度、醇解度。而聚乙烯醇成品后期改性分为增塑改性（包括水及水复配增塑体系、多元醇类增塑体系、离子类物质增塑体系和多元酚类增塑体系）以及后反应改性。文中阐述了热塑改性原理,包括成品前期改性中聚乙烯醇空间位阻和空间规整度的变化,增塑改性中分子链间次价键力的相互作用以及后反应改性中聚乙烯醇网络状结构的形成。此外,对不同热塑改性路线优缺点进行了对比分析,详细介绍了不同改性物质与热加工性能之间的关系,为选择合适的方法制备热塑性聚乙烯醇提供一定的借鉴和参考。基于现有聚乙烯醇热塑改性方法及效果,提出了共聚改性和后反应改性将是聚乙烯醇未来发展的主要方向,以赋予其更加稳定的热加工性能,拓宽应用领域。     

PVA/MMT纳米复合材料的制备方法研究进展

介绍了采用原位聚合插层、溶液插层及熔融插层法制备聚乙烯醇/蒙脱土复合材料的方法。蒙脱土纳米片层的存在延长了气体分子通过复合材料的通道,限制了聚乙烯醇分子的自由体积,减少了聚乙烯醇分子的溶胀及热运动,从而使聚乙烯醇/蒙脱土复合材料的耐水性、热稳定性、气体阻透性及力学性能等都得以提升。蒙脱土在聚乙烯醇基体中以插层或剥离的分散形态存在,剥离型材料力学性能较好,而插层型材料的热稳定性、气体阻透性较好。在PVA基体中,钠基蒙脱土的插层效果优于有机改性蒙脱土。     

改性聚乙烯醇啤酒商标胶耐冰水性的研究

以聚乙烯醇(PVA)和糯玉米淀粉为主要原料,制备了改性聚乙烯醇啤酒商标胶,并着重讨论了糯玉米淀粉、PVA、分散剂、交联剂等用量对改性聚乙烯醇啤酒商标胶耐冰水性能的影响。研究结果表明:当反应温度为82(±2)℃,PVA为4.0g,糯玉米淀粉为7.0g,尿素为5.0g,硫酸铝为3.0g时,该产品的耐冰水性较好。     

聚乙烯醇复合材料在医药领域的应用研究

聚乙烯醇(PVA)作为自然界中唯一的水溶性分子聚合物,具有良好的亲水性能;吸水溶胀性;生物相容性,故以聚乙烯醇(PVA)为基料的复合材料成为众多领域的创新探索与研究发展。本文结合相关文献对聚乙烯醇(PVA)物理共混与化学交联两种改性方法进行分类论述,并介绍了聚乙烯醇PVA在药物载体方面、医学方面与抗菌材料等重要领域的应用。     

聚乙烯醇纤维成纤前后改性方法的研究进展

聚乙烯醇纤维具有耐酸碱、耐磨、可降解、水溶、耐腐耐候和防霉防虫等突出的优点,但存在应用范围较窄的问题。近三十年来,聚乙烯醇纤维的发展经历了服用纤维到产业用纤维的深刻转变,对聚乙烯醇纤维进行功能化改性,是提高其性能并拓宽其应用领域的有效方法。本文以聚乙烯醇纺丝成纤前后两个阶段为重点,系统介绍了纺丝液共混改性和纤维表面修饰两种典型方法。其中,共混改性分为高分子和小分子共混改性,而表面修饰按照其不同的机理则分为表面化学反应改性、表面接枝改性、物理改性等。此外,文中通过对各种改性方法优缺点的分析,阐述了共混改性和表面修饰与性能之间的关系,为选择合适的方法制备特定功能的聚乙烯醇纤维提供一定的借鉴和参考。基于现有聚乙烯醇纤维的改性方法及应用范围,提出了在深度和广度两个层次上不断加强聚乙烯醇纤维的改性研究,赋予其新的性能或满足更高要求的发展趋势。     

Effect of ionizing irradiation and blending of natural rubber latex on polyvinylalcohol gelation by using chemical and freezing–thawing processes for use in the field of construction engineering

The aim of this work is to study the gelation behavior of polyvinylalcohol (PVA) and natural rubber latex (NRL) using two methods: The first was chemical gelation by adding sodium borate as a crosslinking to obtain a modeling clay gel able to draw easily under tension (using drum mill) or by using hand pressing. Irradiation was then applied at 2.5 Mrad to possess more crosslinking effect, where stable and rubbery‐gel shape in the dimension was obtained. The second method, where samples of liquid PVA were frozen and thawed for three consecutive cycles. The obtained gel was quite rubbery but completely soluble in hot water at 70°C. Irradiation was performed at 2.5 Mrad to produce a highly rubbery gel and resistant to boiled water. Also, blending of NRL with PVA induced a significant increase in gel‐elasticity and resistivity to boiled water. Factors affecting the properties of the prepared gel such as gel draw ability and gel strength were studied. The study was supported with thermal and scanning electron microscopy (SEM) to investigate the modification of PVA‐gel behavior through irradiation and blending with NRL processes. The results indicated that the PVA‐gel obtained by chemical method or blended with NRL through freezing–thawing gelation gave a superior ability for cement loading. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

聚乙烯醇膜的改性及应用研究进展

聚乙烯醇（PVA）的改性处理是其应用于膜分离过程必不可少的环节。本文对PVA膜常用的交联、接枝、共混、杂化和取代等改性方法进行了综述,比较了这几种改性方法的优缺点,针对这些改性方法存在的问题,提出了一些改进思路。论文也详细介绍了PVA改性膜在渗透汽化、超滤、纳滤及燃料电池等方面的应用,最后分别对保持良好亲水性PVA膜在渗透汽化脱水领域和高导电率、低甲醇渗透率PVA膜在燃料电池中的应用前景作了展望。     

改性聚乙烯醇膜的研究进展

聚乙烯醇（PVA）因其良好的化学稳定性、耐酸碱、耐有机溶剂性以及优异的成膜性和生物安全性,成为应用最广泛的亲水性膜材料之一。但亲水性PVA膜力学性能弱和耐水性能差等缺点严重限制其实际应用。近些年,人们通过共混、纳米复合、热处理、化学交联以及协同改性等方法对PVA膜进行了大量的改性研究工作并取得了众多成果。本文总结了不同PVA膜改性方法的特点及存在的问题,重点阐述了性能优异的填料在纳米复合改进PVA膜力学性能上的研究现状,简述了共混、热处理、化学交联对改性PVA膜的作用,强调了协同改性对提高PVA膜综合性能的重要意义,为设计和制备高性能的PVA膜提供一定的参考。指出改性后的PVA膜在水处理和食品包装领域具有良好的应用前景。     

水溶性PVA纤维及其制法

水溶性纤维是一种很有价值的功能性差别化纤维,具有广泛的用途。迄今为止,水溶性纤维还只能用PVA制造。本文介绍了水溶性PVA纤维的技术特性和制造方法。在比较分析的基础上论证了干法工艺的优越性。鉴于PVA纤维的结构和性能,开发产业应用领域,特别是其中水溶性和亲水性应用,是一种必然的趋势。这对维纶工业的发展是非常必要的,必须尽快付诸实施。     

Fabrication of water‐soluble poly(vinyl alcohol)‐based composites with improved thermal behavior for potential three‐dimensional printing application

Water‐soluble support materials are essential for fabrication of three‐dimensional printing component, in particular of fused deposition modeling (FDM) process. Poly(vinyl alcohol) (PVA) was considered as a potential ideal candidate used in rapid prototyping technology, while its properties and process‐ability need to be improved for the wide application. This article attempts to use urea/caprolatam (UC) as modification additive for tuning the thermal and mechanical properties of PVA. PVA‐based films with different content of additives were prepared by solution casting method. The results showed that with the increase of UC, PVA films showed decreased crystallinity and melting temperature, while the initial degradation temperature and melt index were increased. The corporation of UC decreased the melting temperature to 173.04 °C and PVA composite with 4.5% crystallinity was fabricated. Due to the formation of hydrogen bonding between UC and the hydroxyl group of PVA, the tensile strength and modulus of PVA were slightly decreased, while strain‐at‐break was significantly enhanced, as high as 470.24%, indicating UC behaved as good plasticizing effect. The microstructure examination via scanning electron microscopy showed that when the content of UC was less than 30% in the composites, homogeneous phase could be observed, indicating good compatibility between these two components. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44966.     

A microstructural approach to adherence mechanism of poly(vinyl alcohol) modified cement systems to ceramic tiles

PVA is a water soluble polymer used as cement modifier. An important modification observed by addition of PVA is the increase of the bond strength between cement paste and aggregate. The purpose of this work was to investigate the effect of PVA on the mechanism of adherence of cement pastes to ceramic tiles. Pastes with and without PVA were applied on the back side of porcelain tiles and after 56 days the microstructures of the interfaces were evaluated by SEM. The mode of rupture changed from mostly interfacial failure to a mixed-mode interfacial-cohesive failure for the paste with polymer addition in which was observed the reduction of the thickness of the porous transition zone between tile and paste bulk. Also, in plain paste the formation of a duplex film (CH plus C-S-H) in contact with tile surface was observed while in modified paste a single layer of C-S-H was identified.     

淀粉对水转印用PVA膜的改性研究

以聚乙烯醇1788(PVA)作为原料,以丙三醇为增塑剂,加入0%~2.5%的淀粉,对水转印PVA膜进行了改性研究。结果表明,加入淀粉后,PVA溶液的粘度增大,膜的溶解时间变长,水上伸长率变小,含水率变小,扯断强度增强,形变缩小;通过膜表面观察,发现淀粉在膜中以聚集颗粒状态存在。研究发现,在淀粉加入PVA后使水转印膜的水溶性得到很大改善。     

水溶性醇酸树脂涂料的进展

综述了水溶性醇酸树脂的设计,合成,改性研究及应用,详细讨论了水溶性醇酸树脂涂料的干燥性能,指出了水溶性醇酸树脂的发展趋势。     

PVA/OPD改性膜对微生物燃料电池性能的影响

为提高微生物燃料电池（MFC）的性能，以聚乙烯醇（PVA）为黏合剂，分别以磷钨酸（PWA）和邻苯二胺（OPD）为改性剂，采用溶液浸渍法制备了PVA/PWA和PVA/OPD改性膜并搭载于MFC系统，以SEM、电化学阻抗谱（EIS）、循环伏安法（CV）、吸水率表征了膜的性能，并考察膜改性对MFC产电量和化学需氧量（COD）去除率的影响。结果显示，PVA/PWA和PVA/OPD改性膜均能在一定程度上提升MFC性能，但PVA/OPD改性膜效果更佳。PVA/OPD改性膜的吸水率为14.49%，较常规Nafion 117膜（NF）提高了126.05%。采用PVA/OPD改性膜的MFC在测试周期内的产电量为101.75 J，较采用NF时提高了587.50%；对阿莫西林制药废水的COD去除率为66.2%，较采用NF时提高了48.4%。基于PVA/OPD的膜改性方法对提高MFC的产电性能和废水处理效果有显著作用。     

Improvement of the water resistance of atactic poly(vinyl alcohol) nanowebs by a heat treatment

Nanoscale materials can be rationally designed to exhibit significantly changed physical, chemical, and biological properties because of the extremely small dimensions. Therefore, atactic poly(vinyl alcohol) (a‐PVA) nanowebs by an electrospinning technique have very high water solubility because of their nanoscale in comparison with microscale materials such as fibers and films. In this study, a‐PVA nanowebs were prepared via electrospinning under suitable conditions to form PVA webs with uniform nanofibers (fiber average diameter = 200 ± 50 nm), not a bead or bead‐and‐string morphology. Furthermore, to improve the water resistance of the water‐soluble a‐PVA nanowebs, the PVA nanowebs were heat‐treated at various heat‐treatment temperatures. The melting temperature of the heat‐treated PVA nanowebs shifted toward a lower temperature with an increase in the heat‐treatment temperature, and this indicated that micronetwork domains formed. Moreover, with the exception of a PVA nanoweb treated at an excessive heat‐treatment temperature, the heat‐treated PVA nanowebs showed higher crystalline and mechanical properties than a pure PVA nanoweb. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007