PVA基膜的研究及应用现状

在对PVA基包装膜和分离膜的研究及应用现状进行综述的基础上,重点介绍了各种PVA分离膜的改性方法、制备工艺、分离性能及其应用,并对PVA膜的未来研究方向提出了展望。     

PVA膜专利预警分析(一)

本文对PVA膜宏观专利数据以及专利技术进行了详细分析。PVA膜专利研究和保护的内容主要涉及原材料、配方、生产工艺、应用领域、装备等多个方面。PVA膜专利技术主要涉及偏光膜、包装膜以及农膜三个方面,其中,偏光膜专利数量最多。PVA偏光膜专利技术主要分为纯PVA膜专利技术、PVA改性技术以及染料/碘系偏光膜技术。在产品研制过程中,重点从原材料的组合应用、生产工艺两个方面着手进行优化。     

PVA膜专利预警分析(二)

本文对PVA膜宏观专利数据以及专利技术进行了详细分析。PVA膜专利研究和保护的内容主要涉及原材料、配方、生产工艺、应用领域、装备等多个方面。PVA膜专利技术主要涉及偏光膜、包装膜以及农膜三个方面,其中,偏光膜专利数量最多。PVA偏光膜专利技术主要分为纯PVA膜专利技术、PVA改性技术以及染料/碘系偏光膜技术。在产品研制过程中,重点从原材料的组合应用、生产工艺两个方面着手进行优化。     

烟用包装膜发展方向分析

介绍了传统型烟用包装膜的重点研究领域,主要包括高挺性、高透明性和高耐磨性。并综述了烟用包装膜的最新研究进展,重点介绍防伪型和环保型烟用包装膜的研究情况。最后介绍了功能型烟用包装膜,如光降解烟膜和生物降解烟膜的研究进展及应用前景。     

可降解包装膜的制备及性能研究

用马来酸酐对玉米淀粉进行酯化处理制得醋酸酯淀粉,以溶液共混法分别制备了原淀粉(ST)/聚乙烯醇(PVA)、醋酸酯淀粉(SA)/聚乙烯醇共混膜,用FTIR表征了共混膜的结构;用DSC分析了共混膜的热性能;比较了共混膜的力学性能。结果表明,共混物的加入破坏了PVA的晶态结构,使共混膜的熔融温度向低温方向移动,热稳定性降低,但SA/PVA共混膜的热稳定大大高于ST/PVA共混膜,说明经酯化处理后淀粉的热稳定性增强。并且SA与PVA的相容性也较ST提高,使其共混膜的力学性能改善。表现为SA/PVA共混膜的力学性能明显高于同比例的ST/PVA共混膜。     

PVA与壳聚糖共混膜的制备及性能研究

用溶液共混法制备PVA与壳聚糖共混膜,用红外光谱法对共混膜进行了表征,并对膜的吸水率、透光率和力学性能进行测试。结果表明,共混膜中PVA分子链与壳聚糖分子链有一定的相互作用,壳聚糖的引入有利于改善PVA的透光性和降低其吸水率。     

高分子薄膜防锈技术研究与应用

利用高分子PVA膜具有独特的强力粘接性、皮膜柔韧性、平滑性、耐油性、耐溶剂性、保护胶体性、气体阻隔性、耐磨性以及经特殊处理具有耐水性的特点,制备PVA膜,试验防锈性能。采用对照法试验了不同条件PVA膜的防锈性能效果,通过对比得出PVA膜的最佳试验条件,添加有液体石蜡和乳化剂的PVA膜防锈效果最佳。PVA防锈膜具有广阔的应用前景。     

聚合物膜的研制

以聚丙烯腈(PAN)／聚乙烯醇(PVA)合金为膜材料，用液-固相转化法成膜制备PAN/PVA体系的非对称型合金微滤膜。研究了铸膜液浓度、聚合物共混配比、铸膜液温度溶剂蒸发时间、凝胶浴温度对膜结构和膜性能的影响。结果表明：采用了液-固相转化法成膜，可制成孔径为0．5～5．0μm的非对称性PAN/PVA合金微滤膜。     

功能膜材料发展概况及应用进展（续完）

概述了3类新型功能膜材料的最新研究进展,包括PVDF中空纤维微滤超滤膜、低压大通量纳滤膜、正渗透膜、膜蒸馏、血液透析膜、空气能量回收膜等分离膜,锂离子电池隔膜、燃料电池质子交换膜、电渗析膜等离子交换膜,PVDC包装膜、太阳能电池背板膜等封装膜。以及中科院宁波材料所功能膜课题组在此领域的基础研究和应用情况。认为我国应大力发展新型分离膜．离子交换膜的研究主要向高性能、低成本方向发展,封装膜材料需要发展新型绿色、环保的高阻隔材料以及绿色加工方法。     

武大研制出食用性内包装膜

武汉大学科研人员继2000年研制出魔芋包装膜以后,今年该校又将这种生物可降解膜的原料延伸到玉米、马铃署身上,从而使淀粉系列包装膜又添新品。     

淀粉/聚乙烯醇活性包装薄膜及其在食品包装应用中的研究进展

综述了淀粉/聚乙烯醇（PVA）活性包装薄膜及其在食品包装中的研究进展,主要对从不同比例共混、疏水改性、增强改性等方面对淀粉/PVA薄膜的改性研究,从功能特性和活性物质对薄膜性能的影响2个方面对淀粉/PVA活性薄膜研究和薄膜在食品包装中的应用3个方面进行了归纳总结,旨在为以淀粉/PVA为基材的活性包装薄膜研究提供参考。     

Multifunctional and pH-responsive dialdehyde cellulose/polyvinyl alcohol composite film reinforced with curcumin

The rational design of food packaging films with good antimicrobial activity, antioxidant activity, and monitorability is of great importance in intelligent packaging. In this study, an active composite film was prepared by adding curcumin to a dialdehyde cellulose (DAC)/polyvinyl alcohol (PVA) matrix. It was found that the Cur/DAC/PVA composite film exhibited optimal tensile strength at 30°C. The tensile strength of the composite film control PVA/DAC film was observed to increase by 176% due to the affection of hydrogen bonding. Under the influence of curcumin, the UV barrier property and antioxidant activity of the composite film were significantly increased, and the ABTS⁺• was removed by 0.5Cur/DAC/PVA up to 88% at low curcumin content. The water solubility and water vapor permeability were both reduced to some degree. It was also observed that composite film displayed an inhibitory effect on the growth of Staphylococcus aureus bacteria. Meanwhile, the Ritger and Peppas release model was used to study the release control capability of curcumin. Furthermore, the Cur/DAC/PVA composite film demonstrated excellent color response to pH, which it they could be used for intelligent packaging with real-time visual monitoring.     

The influence of cinnamon and litsea cubeba essential oils on methylcellulose films

The aim of this study was to prepare active, biodegradable methylcellulose films and evaluate their properties after incorporating cinnamon (Cinnamomum cassia) and litsea cubeba (Litsea cubeba) essential oils. The properties of the methylcellulose films were modified with the addition of essential oils. The surfaces were smooth and homogeneous in all samples. The film with cinnamon oil showed higher antibacterial activity against Staphylococcus aureus and Escherichia coli and the film with litsea cubeba showed higher antioxidant activity against ABTS radical. The biodegradation time of the films in black sand and beach soil was 20 days. The films produced that presented the highest potential to become active packaging were the film with litsea cubabe oil as antioxidant packaging and the film with cinnamon oil as antibacterial packaging.     

The effect of polymer surface modification via interfacial polymerization on polymer–protein interaction

Membrane separation is an important processing technology used for separating food ingredients and fractionating value‐added components from food processing byproducts. Long‐term performance of polymeric membranes in food protein processing is impeded by the formation of fouled layers on the membrane surface as a result of protein adsorption onto the membrane surface. Surface modification of synthetic membranes, i.e., changing surface characteristics to reduce protein adsorption permanently, is one of the innovative ways of reducing the fouling of membrane surfaces. In this study, surface modification of flat‐sheet ultrafiltration membrane, polyethersulfone (PES), was investigated in improving the hydrophilicity of PES surfaces, thereby reducing adsorption of the protein caused by hydrophobic–hydrophobic interaction between the protein and the membrane. Hydrophilic polymer grafting through thin‐film composite using interfacial polymerization was employed to improve the hydrophilicity of the commercial PES membranes. Poly(vinyl alcohol), poly(ethylene glycol), and chitosan were chosen as hydrophilic polymers to graft on PES membrane because of their excellent hydrophilic property. Modified PES membranes were characterized by contact angle, FTIR, XPS, and AFM. Contact angles of modified PES membranes were reduced by 25 to 40% of that of the virgin PES membrane. XPS spectrum supported that the PES membranes were successfully modified by interfacial polymerization. Tapping‐mode AFM was used to examine the changes in surface topography of modified PES membranes. The PES membranes modified by interfacial polymerization showed lower roughness (from 1.2 to 2.0 nm) than that of virgin PES membrane (2.1 nm). The results of these instrumental analyses indicated that the PES membranes were successfully enhanced hydrophilically through interfacial polymerization. The protein adsorption on the modified membranes was reduced by 30 to 35% as a result of surface modification of the PES membranes using interfacial polymerization technique. Published 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Sesame Oil Oxidation Control by Active and Smart Packaging System Using Wheat Gluten/Chlorophyll Film to Increase Shelf Life and Detecting Expiration Date

In this study, a smart biodegradable film based on wheat gluten modified with chlorophyll (WG/Ch) is presented. The effect of chlorophyll on the antioxidant activity and mechanical properties of WG/Ch film is studied. Scanning electron microscopy and Fourier‐transform infrared spectroscopy (FT‐IR) analyses are used to study the structure and chemical composition of gluten‐based films. The WG/Ch film is used in the packaging of sesame oil. The effect of WG/Ch film on increasing the shelf life and detecting expiration time of oil is studied. FT‐IR results show that weak interactions are created between gluten and chlorophyll. The antioxidant activity of the WG film is 60% and it increases to 85% by the addition of chlorophyll. The results show that with the increasing storage time of oil samples, oxidative indices are increased, but the WG/Ch film decreases the sesame oil oxidation significantly (almost in the all oxidative indices 50% decrease is observed). Practical Applications: The WG/Ch film is used in the packaging of sesame oil. The effect of WG/Ch film on the increasing of shelf life and detecting expiration time of oil is studied. By increasing storage time and oxidant, acidity, acid number, PA, and oil color change are increased, but the WG/Ch active film decreases the sesame oil oxidation significantly. Also, by examining the color properties of the active film, it is observed that with increasing storage time and oxidant percent, the color of the film is changed (from green to yellow), which can be used to estimate the oil expiration time. It should be mentioned that the film's color changes are visible to the naked eye.     

New production technologies and applications of poly(vinyl alcohol) film

The following aspects of the manufacture, properties and applications of biaxially oriented poly(vinyl alcohol) (PV-OH) films are discussed: selection of starting PV-OH; method of production by successive biaxial orientation: technical aspects of production; characteristics and applications of the film. Biaxially oriented PV-OH films have good antistatic properties, good thermal resistance, oil and solvent resistance, and excellent gas barrier properties, and are used in food packaging applications. The following aspects of the manufacture, properties and applications of poly(vinyl alcohol) film produced by a blown film technique are discussed: selection of starting PV-OH; process for the production of hot-water-soluble (HWS) film; technical aspects of film production; characteristics and applications of the film. Blown films, which are hot-water-soluble, are produced in tubular form, for conversion into disposable laundry bags.     

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。     

Fabrication of polyamide thin film nanocomposite reverse osmosis membrane incorporated with a novel graphite-based carbon material for desalination

The properties of polyamide (PA) thin film composite (TFC) membranes are affected by many variables, especially the additives in the process of interfacial polymerization that play an important role in the properties of membranes. In this study, a new type graphite carbon was added into organic phase containing trimesoyl chloride for interfacial polymerization with aqueous phase containing m-phenylenediamine to prepare modified polyamide thin film nanocomposite (TFN) membranes for reverse osmosis (RO) adhibition. Polysulfone ultrafiltration membranes were used as the carrier of the interfacial polymerization. The concentration of graphite carbon was selected from 0.002 to 0.01 wt%. The polyamide nanocomposite membrane prepared with the concentration of 0.004 wt% graphite carbon showed the best RO desalination performance, which the water flux of this TFN membrane is over 2.3 times as much as pristine TFC membrane, and the salt rejection is over 99%. This article provides a well-performing polyamide thin film nanocomposite membrane modified by a new-type carbon nanoparticles consequently.     

pH可控PVAm-g-PBA/PVA层层自组装 在纤维素膜上的应用

通过酰胺化反应将4-羧基苯硼酸(PBA)接枝到聚乙烯胺(PVAm)高分子链上,制得改性聚乙烯胺(PVAm-g-PBA),利用FTIR和1HNMR对其结构进行了表征。采用硅晶片和聚苯乙烯微球(PS)作为模拟物,将PVAm-g-PBA和聚乙烯醇(PVA)组装到其表面并研究了自组装过程中基材表面电荷的变化规律及自组装膜层厚度的变化。将PVAm-g-PBA与PVA通过pH可控的层层自组装方法处理再生纤维素膜表面。结果表明:PVAm-g-PBA的等电点为pH=7.9;在p H=9.5、与PVA组装上30层高分子膜时,再生纤维素膜的抗张强度与断裂伸长率分别提高了53%和76%。处理后的再生纤维素膜的机械性能得到了明显改善。     

醋酸乙烯/乙烯/丙烯酸酯多元共聚乳液开发与应用研究

研究了醋酸乙烯/乙烯/丙烯酸酯多元共聚乳液的合成.在高压反应釜中采用间歇聚合工艺进行乳液聚合,使用聚乙烯醇作为主要保护胶体,采用非离子和阴离子复合乳化剂以及氧化-还原引发体系,通过引入丙烯酸酯类软单体,实现醋酸乙烯/乙烯/丙烯酸酯多元共聚,生产出低温柔性好、对非极性材料(例如BOPP)具有优异粘接性能的新型多元改性共聚VAE乳液.用于防水涂料和包装行业,效果优良.