A Hybrid Membrane of Poly(vinyl alcohol) and Phosphotungstic Acid for Fuel Cells

Proton conducting membranes composed of phosphotungstic acid (PWA) and poly(vinyl alcohol) (PVA)were prepared. Conductivity and Fourier transform infrared spectrometer(FTIR) measurements show that most ofthe acid embedded are stable in the PVA matrix when the membrane is immerged in water or methanol solution atroom temperature. Conductivity of the composite membranes scatters around 10-3 S.cm-1 at room temperature.The methanol crossover through the membranes is about an order of magnitude lower than that through Nafion117 membrane.

Preparation of Macroporous Poly (vinyl alcohol-co-triallyl isocyanurate) Beads Bearing Aminocarboxylic Acid as Functional Groups by Suspension Polymerization

Macroporous poly (vinyl acetate-co-triallyl isocyanurate) beads were prepared with suspension polymerization method. The copolymer beads were then transformed into poly (vinyl alcohol-co-triallyl isocyanurate) by ester exchange reaction. Aminocarboxylic acids were immobilized on the copolymer beads by the esterification of hydroxyl groups with diethyl-lenetriaminepentaacetic bisanhydride. The weak acid exchange capacities, specific surface areas and mean pore diameters of the resultant resin beads were measured.

Synthesis of Bifunctional Poly(Vinyl Phosphonic Acid-<i>co</i>-glycidyl Metacrylate-<i>co</i>-divinyl Benzene) Cation-Exchange Resin and Its Indium Adsorption

Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodi-acetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The synthesized PVGD and IPVGD resins were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury porosimetry. The cation-exchange capacity, the water uptake and the indium adsorption properties were investigated. The cation-exchange capacities of PVGD and IPVGD were 1.2 - 4.5 meq/g and 2.5 - 6.4 meq/g, respectively. The water uptakes were decreased with increasing contents of divinyl benzene (DVB). The water uptake values were 25% - 40% and 20% - 35%, respectively. The optimum adsorption of indium from a pure indium solution and an artificial indium tin oxide (ITO) solution by the PVGD and IPVGD ion-exchange resins were 2.3 and 3.5 meq/g, respectively. The indium adsorption capacities of IPVGD were higher than those of PVGD. The indium ion adsorption selectivity in the artificial ITO solution by PVGD and IPVGD was excellent, and other ions were adsorbed only slightly.

Removal of manganese from waste water by complexation-ultrafiltration using copolymer of maleic acid and acrylic acid

Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.

PREPARATION OF PERFLUOROOCTANOYL-MODIFIED POLY(VINYL-ALCOHOL)S AND THEIR ADSORPTION AT AN AIR-WATER INTERFACE

Perfluorooctanoyl modified poly(vinyl alcohol)s (FPVA) were prepared by means of substituting a small amount of hydroxyl groups on the backbone of poly(vinyl alcohol), for which the initial degree of polymerization is equal to 1750. The substitution extent, defined by the number of substituting units in a chain, for the four FPVA samples was in the range of 0.5-5 perfluorooctanoyl groups per chain. The FPVA samples with the highest substitution extent still had good solubility in water. It was shown by experimental measurement at 30.0 +/- 0.1 degreesC that the surface tension of the aqueous solution of the highest substituted FPVA decreased to 16.6 mN/m at a higher concentration, e.g. about 0.1 g/mL. Obviously, macromolecules of FPVA exhibit a very strong tendency to adsorb at the air-water interface, because the hydrophobic perfluorooctanoyl groups in FPVA have a very high surface activity as they are in small molecular fluorinated surfactants. The chain conformation of such a model polymer adsorbed on the air-water interface was also discussed.

Studies on interacting Blends of Acrylated Epoxy resin based Poly(Ester-Amide)s and Vinyl EsterResin

Epoxy resin based Unsaturated poly(ester-amide) resins (UPEAs) can be prepared by many methods but here these were prepared by reported method [1]. These UPEAs were then treated with acrylotl chloride to afford acrylated UPEAs resin (i.e. AUPEAs). Interacting blends of equal proportional AUPEAs and vinyl ester epoxy (VE) resin were prepared. APEAs and AUPEAs were characterized by elemental analysis, molecular weight determined by vapour pressure osmometer and by IR spectral study and by thermogravimetry. The curing of interacting blends was monitored on differential scanning calorimeter (DSC). Based on DSC data in situ glass reinforced composites of the resultant blends have been prepared and characterized for mechanical, electrical and chemical properties. Unreinforced blends were characterized by thermogravimetry (TGA).

磺化聚乙烯醇/侧链磺化聚芳醚酮交联复合膜的制备与性能

通过溶液共混热处理方法,制备了磺化聚乙烯醇(SPVA)含量不同的SPVA/侧链磺化聚芳醚酮交联复合膜(Cr-SSPxx)。交联网络结构有效增强了交联复合膜的力学性能、热稳定性、氧化稳定性及尺寸稳定性,扫描电镜显示,交联复合膜呈现了更好的相容性和均一性。随交联度增加,交联复合膜的溶胀率呈现明显下降趋势,在25℃和80℃时,Cr-SSP30膜的溶胀率分别仅有3.7%和7.6%。由于SPVA对醇有阻碍作用,以及交联网络结构增加了膜的致密性,故该系列Cr-SSPxx膜展现出非常优秀的阻醇性能,交联复合膜的甲醇渗透率明显低于纯S-SPAEK膜和磺化聚乙烯醇/侧链型磺化聚芳醚酮复合膜,Cr-SSP30膜的甲醇渗透率仅为9.4×10^(-8) cm^(2)/s。虽然与磺化聚乙烯醇/侧链型磺化聚芳醚酮复合膜相比,交联复合膜的质子传导率有所降低,但由于独特的侧链磺化结构能够促进质子传导,质子传导率最低的Cr-SSP30膜的传导率在25℃和80℃时也都分别达到了0.034 S/cm和0.065 S/cm,同时表现出了更高的质子选择性,能够满足直接甲醇燃料电池(DMFC)的使用要求,有望在DMFC中得到应用。

Cells Attachment Property of PVA Hydrogel Nanofibers Incorporating Hyaluronic Acid for Tissue Engineering

In this work, we report the fabrication and cell affinity studies of the poly(vinyl alcohol) (PVA)/hyaluronic acid (HA) cross-linked nanofibers via electrospinning and post cross-linking. FT-IR and TGA analysis demonstrate that HA is not influenced by acid environment such as HCl vapor during cross-linking, and well incorporated into PVA nanofibers. Swelling behavior and cell adhesion of the PVA/HA hydrogel nanofibers are investigated and compared with pure PVA hydrogel nanofibers. It is expected that the nanofibrous PVA/HA hydrogel fibers could be a promising scaffold for cell culture and tissue engineering applications.

聚乙烯醇纤维增强聚乳酸复合材料的制备及性能研究

以聚乳酸(PLA)和高强高模聚乙烯醇(PVA)纤维为原料,通过熔融共混热压成型工艺制备了不同PVA纤维含量的PLA/PVA复合材料,研究了复合材料的相形态、玻璃化转变、结晶和熔融行为以及力学性能。结果表明:低含量的PVA纤维能均匀地分散在PLA基体中,当纤维质量分数达到20%时,纤维发生团聚。差示扫描量热仪测试结果表明PVA纤维在PLA结晶过程中起到了成核作用。随PVA纤维含量增加,PLA的结晶度增加。此外,动态力学行为表明PVA纤维含量的增加有助于提高复合材料储能模量和刚性。复合材料的拉伸和弯曲模量随PVA纤维含量的增加而增加,当PVA纤维质量分数为20%时,拉伸和弯曲模量达到最大,与纯PLA相比,复合材料的拉伸和弯曲模量分别提高了43.5%和38.6%。但是,PVA纤维的加入并没有使复合材料的拉伸和弯曲强度得到较大改善。

单宁酸/聚乙烯醇的阻燃性能

采用模压成型的方法制备了单宁酸/聚乙烯醇(TA-PVA)共混物,并研究了不同TA/PVA配比对TA-PVA共混物的阻燃性能的影响。通过锥形量热仪、热重分析仪(TGA)、差示扫描量热仪(DSC)、垂直燃烧(UL-94)测试仪和极限氧指数(LOI)测试仪等对制备的TA-PVA共混物的阻燃性能进行了测试。结果表明,TA的加入能提高PVA的阻燃性能。TA和PVA能够通过分子间氢键形成稳定的TA-PVA共混物。当TA-PVA共混物中TA含量增加,所制备得到的TA-PVA共混物的热稳定性增加,玻璃化转变温度提高。当n(TA)∶n(PVA)=1∶50时,TA-PVA共混物的LOI值达到31.6%,UL-94等级为V-1级,热释放速率峰值从634.9 kW/m^(2)降至328.1 kW/m^(2),烟气产生速率从0.18 m^(2)/s降至0.10 m^(2)/s。

聚乳酸/塑化聚乙烯醇合金开孔发泡行为研究

以聚乳酸(PLA)为基体,加入不同含量的塑化聚乙烯醇(CPVA),通过熔融共混法制备PLA/CPVA合金样品。以超临界CO_(2)为物理发泡剂,采用釜压发泡和粒子沥滤法成功制备出PLA/CPVA合金开孔泡沫。结果表明,随着CPVA含量的增加,PLA的结晶温度下降,结晶度先上升后下降,熔体黏弹性改善;随着CPVA含量的上升,PLA/CPVA合金开孔泡沫的发泡倍率先减小后逐渐增大,开孔率逐步提高;当CPVA含量为50%(质量分数,下同)时,PLA/CPVA合金开孔泡沫的发泡倍率为23.1倍,开孔率达到了91.6%。

辐照交联PVC/环氧树脂固化复合发泡材料的制备及性能

采用熔融共混法和辐照交联工艺成功制备了一系列聚氯乙烯(PVC)/环氧树脂(E-12)/马来海松酸酐(MPA)复合发泡材料。通过傅里叶变换红外光谱仪(FTIR)和核磁共振仪(1H-NMR、13C-NMR)表征了MPA的化学结构;通过凝胶含量、力学性能、扫描电子显微镜(SEM)和吸水率等试验,探究了E-12/MPA(EM)固化物含量对PVC/E-12/MPA复合发泡材料性能的影响。结果表明,当EM固化物含量为10%(质量分数,下同)时,PVC/E-12/MPA复合发泡材料的凝胶含量为42.3%,较改性前提高了9.9%,拉伸强度提高了23.4%,压缩强度提高了26.7%,压缩模量提高了32.5%;断裂伸长率从286.11%降至217.68%,吸水率从改性前1.5%增至3.4%,同时具有优异的泡孔结构。

Metal lanolin fatty acid as novel thermal stabilizers for rigid poly(vinyl chloride)

The synergistic stabilization effect of different metal lanolin fatty acids as natural-based thermal stabilizers for poly（vinyl chloride） （PVC） including calcium lanolin fatty acid （Calan2）,zinc lanolin fatty acid （Znlan2） and lanthanum lanolin fatty acid （Lalan3） were studied through Congo red testing,color measurements,FTIR analyses and thermal behavior in this paper. The results showed that Lalan3/Calan2/Znlan2 stabilizers exhibited more excellent thermal stabilization efficiency to PVC than Calan2/Znlan2 thermal stabilizers,and the optimal mass ratio of Lalan3/Calan2/Znlan2 was 8：9：3. At last,the effect of degradation mechanism on PVC and synergistic stabilization was also investigated by FTIR analyses and thermal behavior.

Folic Acid Modified Electrospun Poly(vinyl alcohol)/Polyethyleneimine Nanofibers for Cancer Cell Capture Applications

Capture and detection of metastatic cancer cells are crucial for diagnosis and treatment of malignant neoplasm. Here, we report the use of folic acid （FA） modified electrospun poly（vinyl alcohol） （PVA）/polyethyleneimine （PEI） nanofibers for cancer cell capture applications. Electrospun PVA/PEI nanofibers crosslinked by glutaraldehyde vapor were modified with FA via a poly（ethylene glycol） （PEG） spacer, followed by acetylation of the fiber surface PEI amines. The formed FA-modified nanofibers were well characterized. The morphology of the electrospun PVA/PEI nanofibers is smooth and uniform despite the surface modification. In addition, the FA-modified nanofibers display good hemocompatibility as confirmed by hemolysis assay. Importantly, the developed FA-modified nanofibers are able to specifically capture cancer cells overexpressing FA receptors, which were validated by quantitative cell counting assay and qualitative confocal microscopy analysis. The developed FA-modified PVA/PEI nanofibers may be used for capturing circulating tumor cells for cancer diagnosis applications.

聚乳酸接枝乙烯基吡咯烷酮的初步研究

为改善聚（Ｄ，Ｌ乳酸）（ＰＤＬＬＡ）的亲水性，以过氧化二苯甲酷为引发剂，四氢呋喃为溶剂，进行了 ＰＤＬＬＡ接枝乙烯基吡咯烷酮（ＶＰ）的试验．ＩＲ和１Ｈ ＮＭＲ测试结果表明：ＰＤＬＬＡ可与 ＶＰ实现接枝反应，摩尔接枝率为１．０％－１．６％．与ＰＤＬＬＡ相比，接枝产物的［η］ 值下降，但吸水率增加、接触角变小，亲水性有所改善．

PVA-SA/CS双极膜制备及在电解制备羟基新戊酸中的应用

将柔性链聚乙烯醇（PVA）分别与天然高分子海藻酸钠（SA）、壳聚糖（CS）共混，以增强其柔韧性及双极膜界面层的相容性。分别以FeCl3和戊二醛为交联剂，对PVA／SA和PVA／CS进行改性，制备了PVA-SA／CS双极膜，其溶胀度为25％，80％。用红外光谱和扫描电子显微镜对膜成分与形貌进行了表征。结果表明，PVA-SA／CS双极膜致密，表面均匀，未见孔隙。阴离子交换层（GA-PVA／CS）中含有-N=C官能团，阳离子交换层（Fe-PVA／SA）中含有-COO^-官能团。以PVA-SA／CS双极膜为电解槽的隔膜，间接电氧化羟基新戊醛为羟基新戊酸，槽电压稳定，在电流密度28×10^-3 A／cm^2下，最大电流效率为68．9％，平均电流效率为52．2％。

绿色增塑剂的研究进展

综述了国内外关于绿色增塑剂领域的最新研究应用进展,主要介绍了柠檬酸酯类、植物油基及环氧酯类、聚酯类和新型非邻苯类等增塑剂的制备方法、物理化学性质、热力学性能和力学性能以及在材料制品中的应用现状,并对其进行了比较;最后,对绿色增塑剂的应用前景做了展望。

纳米纤维素晶体和柠檬酸改性聚乙烯醇薄膜的制备及性能

以球形纳米纤维素晶体(NCC)作增强相、柠檬酸作交联剂对聚乙烯醇(PVA)进行改性,制备了PVA/NCC纳米复合薄膜和柠檬酸交联PVA/NCC纳米复合薄膜。通过热重分析、差热分析、吸水实验和拉伸实验考察了NCC的添加和柠檬酸的交联对薄膜热性能、耐水性和力学性能的影响。结果表明,与纯PVA薄膜相比,改性PVA薄膜的起始分解温度升高、熔融/结晶峰向高温方向移动、吸水率降低;只用NCC或柠檬酸对PVA改性时,所得PVA/NCC纳米复合薄膜、柠檬酸交联PVA薄膜的力学性能均对环境湿度敏感;同时用NCC(m(NCC)/m(PVA)=6/100)和柠檬酸(m(柠檬酸)/m(PVA)=3/100或m(柠檬酸)/m(PVA)=4.5/100)对PVA改性时,所得柠檬酸交联PVA/NCC纳米复合薄膜的力学性能不随环境湿度变化。

环氧脂肪酸稀土的合成及其对PVC热稳定作用的研究

制备了环氧基保留完好的高纯度环氧脂肪酸稀土。研究发现环氧脂肪酸稀土对PVC的热稳定作用类似于硬脂酸稀土 ,具有长期型热稳定剂的特征 ,但其热稳定效能明显优于后者 ,可代替硫醇辛基锡达 5 0 %而不降低热稳定性 ,而硬脂酸稀土只能代替约 2 5 %。

氨基酸镧在PVC中的热稳定性能

合成了8种氨基酸镧热稳定剂,并将其应用于PVC中。采用刚果红法、热老化烘箱法、电导率法测试了氨基酸镧的热稳定性,并与常见热稳定剂进行复配实验。结果表明:色氨酸镧的热稳定性较好,与硬脂酸钙、季戊四醇按份数比2/1/1复配后能更大程度地延长PVC的热稳定时间,改善试样初期着色,热降解活化能比市售钙锌稳定剂提高了2.83 kJ/mol,表现出更优的热稳定性能。