功能化聚乙烯膜的制备及性能研究

以高压聚乙烯（LDPE）膜为原料，采用紫外光辐照引发LDPE膜表面接枝丙烯酸；研究发现，当接枝率达到2．5g/m^2时，丙烯酸接枝LDPE膜的润湿性达到平衡值；接枝改性后，LDPE膜的润湿性、透湿性都得到改善；IR光谱显示丙烯酸已成功接枝到LDPE膜上；DSC热分析显示接枝改性不影响LDPE膜材料的晶型结构。     

PTFE中空纤维膜表面改性及组件浇铸技术的研究

采用浸渍丙烯酸、丙烯酸丁酯、复配功能性溶液和等离子体接枝丙烯酸的处理方式对聚四氟乙烯中空纤维膜进行改性处理,在中空纤维膜表面沉积、接枝活性层,改善聚四氟乙烯中空纤维膜表面的润湿性和黏结性能,并与传统钠萘溶液处理的改性效果进行了比较。通过扫描电镜(SEM-EDX)、傅里叶变换衰减全反射红外光谱(ATR-FTIR)、接触角测试表征聚四氟乙烯膜改性前后表面的形态结构及润湿性能。研究表明,浸渍丙烯酸溶液的中空纤维膜表面沉积了聚丙烯酸活性层,润湿性能提高;等离子体接枝丙烯酸改性处理的中空纤维膜表面引入了—COOH,—C=C—等活性基团,润湿性能有所改善。通过拉伸黏结强度、渗漏压力测试聚四氟乙烯中空纤维膜组件中中空纤维膜与胶黏剂间的黏结强度。结果表明,浸渍丙烯酸、丙烯酸丁酯、复配功能性溶液的中空纤维膜的最大拉伸载荷分别为61.9、58.5、43.5 N时从胶黏剂中滑脱,当水压达到0.15 MPa时均出现了渗漏;等离子接枝丙烯酸处理的中空纤维膜的最大拉伸载荷为60.9 N,并且在0.15 MPa的水压下未发生渗漏,适用于膜组件浇铸。     

腐殖酸表面接枝对丙烯酸类超强吸水树脂的改性研究

采用腐殖酸（HA）溶液处理丙烯酸类超强吸水树脂颗粒，对丙烯酸类超强吸水树脂颗粒进行表面接枝改性，研究了HA表面改性对丙烯酸类超强吸水树脂颗粒吸水性能、吸水速度以及表面结构的影响。结果表明，HA改性后的吸水树脂颗粒其吸收蒸馏水的能力提高30％，吸收生理盐水的能力可以提高1．1倍，达到饱和溶胀所需要的时间降低，防潮性能大大提高，电镜照片显示吸水树脂颗粒表面形成明显的层状膜。     

丙烯酸接枝PVDF超滤膜亲水改性研究

采用自由基聚合方法将丙烯酸接枝到经过消去反应形成一定C=C含量的PVDF中空纤维超滤膜表面,改善了膜表面的亲水性。依据超滤膜的孔径结构要求,调控丙烯酸接枝链的长度。通过XPS、SEM和水通量实验分析效果表明,丙烯酸接枝改性PVDF中空纤维超滤膜表面引入了-COOH和-OH亲水基团,膜表面和孔壁形成的亲水层没有改变膜表面的孔径尺寸,水通量比改性前提高了280%以上。     

低温氨等离子体改性聚醚砜超滤膜气相接枝丙烯酸

采用低温氨等离子体处理和气相接枝丙烯酸对聚醚砜(PES)膜进行表面改性,以提高超滤膜亲水性和抗污染能力。考察了改性膜物理及化学特性变化,并研究了改性膜的通量及截留率特性。结果表明,改性膜表面接枝有亲水基团,水接触角由原始的67°降低至9°,亲水性能明显提高;纯水通量、牛血清蛋白通量和截留率均大于原始膜。     

接枝丙烯酸亲水化改性聚砜超滤膜及其在多肽分离中的应用

采用丙烯酸亲水化改性聚砜中空纤维超滤膜。以四氯化锡为催化剂，磷酸为催化助剂，通过检测接触角，优化了丙烯酸浓度与催化剂用量（摩尔比1:0.05）、反应温度（30ºC）和反应时间（60min）等改性条件。红外光谱检测表明羧基被成功地接枝于膜表面；扫描电镜分析说明表面改性未对膜面和膜骨架造成损坏。通过超滤不同浓度的牛血清白蛋白（BSA）溶液，证明改性膜（MM）比未改性膜（UMM）具有更好的抗蛋白吸附性能。将MM应用于酪蛋白酶解物活性多肽的分离制备时，优势体现于长期操作中较高的渗透通量与渗透液中更为合理的分子量分布两方面。     

Ar等离子体改性PTFE膜接枝丙烯酸的研究

本研究利用Ar等离子体为引发手段对PTFE膜进行表面处理,最终实现在PTFF膜表面接枝丙烯酸。通过XPS和ATR-FTIR对改性膜的表面进行表征,表明在PTFE膜的表面形成一层聚丙烯酸（PAAc）薄膜。PTFE—g—PAAc膜的表面亲水性及其表面稳定性比等离子改性PTFE膜具有较大的改善,克服了等离子体改性效果不稳定的缺点。本研究拓展了PTFE膜材料在其他各相关领域的应用,对其他高分子材料也有一定的借鉴意义。     

紫外接枝改性PP中空多孔膜表面亲水性研究

采用紫外辐照接枝方法,以二苯甲酮(BP)为光敏剂,丙烯酸为单体,对聚丙烯(PP)中空多孔膜表面进行接枝聚合改性。研究了辐照时间、光敏剂浓度、单体体积分数和接枝时间对膜表面接枝率的影响,并以红外、扫描电镜、水通量等表征测试方法,观察了改性前后多孔膜的表面结构及亲水性效果。结果表明,在紫外光照射时间25 min,光敏剂浓度4×10~(-3)mol/L,丙烯酸体积分数35%,反应时间6 h的反应条件下,PP膜水通量最佳,亲水性得到明显改善。     

聚偏氟乙烯中空纤维膜的低温等离子体改性及动电特性研究

采用低温等离子体设备改性聚偏氟乙烯(PVDF)中空纤维膜,以接枝率、力学性能、膜面元素含量的变化以及膜面形态为评价指标考察改性膜物理及化学特性的变化,并研究了改性膜的清水通量及膜面的动电特性.元素能谱分析表明,经丙烯酸胺(AM)接枝改性后膜表面的N.O含童明显增加.SEM照片及拉力试验反映出改性膜的膜孔径变小,力学性能良好.改性膜的荷电性能明显优于原膜,且接枝单体质量分数为5%的改性膜的清水通量大于原膜.     

丙烯酸改性聚氨酯的合成与性能的研究

采用聚丙烯酸酯与聚氨酯共混、以水性聚氯酯为种子乳液进行丙烯酸种子乳液聚合以及水性聚氨酯与丙烯酸接枝共聚3种方法分别得到丙烯酸改性水性聚氯酯，通过激光散射粒径仪测定乳胶粒的粒径、乳胶膜的透明性、傅里叶变换红外光谱(FTIR)结构分析以及扫描电镜(SEM)对乳胶膜结构和表面形貌进行分析。结果表明：采用种子乳液聚合反应和接枝反应所得到的丙烯酸改性水性聚氯酯乳液乳胶粒粒径比水性聚氨酯的粒径显增大，表现出良好的相容性；由种子乳液聚合和接枝聚合制备的丙烯酸改性水性聚氯酯胶膜中颗粒与颗粒之间结合紧密，表面光亮、透明。     

辐照接枝丙烯酸改性聚砜超滤膜

采用液相共辐照技术在聚砜超滤膜上接枝丙烯膜，通过改变辐照剂量和丙烯酸单体浓度可以获得具有不同接枝率的改性聚砜膜。实验结果表明，随着接枝率的提高，改性聚砜抗蛋白质吸附污染的能力显著增强，并且认为接枝膜的亲水性提高是膜污染减轻的主要原因。     

Studies of performances by the interchanging of the sequence of the photomodified layer in the thin film composite (TFC) membrane

UV‐initiated photomodification by a hydrophilic functional moiety (i.e., acrylic acid) was performed in and on a polypiperazineamide thin‐film composite membrane. The sequence of the bilayers (i.e., acrylic acid and polypiperazineamide) was altered on a polysulfone membrane. The size exclusion order through the membranes was Atrazine > Simazine > 2,4,6‐Trichlorophenol > 2,4‐Dichlorophenol according to the molecular size, which was calculated by the quantum mechanical approach. Apart from the molecular size, the polarity and hydrophobicity of the molecules also influenced the separation. The performance of the membranes is based on size exclusion. The membrane with an inner layer of acrylic acid showed more blocking effect than the membrane with the same layer on the top of polypiperazineamide membrane and the unmodified polypiperazineamide membrane. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Dye removal from colored textile wastewater using acrylic grafted nanomembrane

In this paper, the dye removal ability of the acrylic grafted polysulfone nanomembrane using ultraviolet radiation was studied to remove dyes from colored textile wastewater. Acrylic acid was used to modify polysulfone ultrafiltration membrane. The effect of different operating parameters such as pressure, salt concentration and chemical structure of dyes was evaluated. Data indicated that the photografted membrane has acceptable performance both in terms of flux and rejection. The dye rejection and hydraulic permeability were 86–99.9% and 7.6 L m^{− 2} h^{− 1} bar^{− 1}, respectively. It was found that the rejection of dyes decreased with salt concentration due to a decrease of the Donnan effect. Also, the low molecular weight dyes and highly charged dyes were more sensitive in the presence of salts. Addition of 80 mM Na₂SO₄ in dye solution decreased the dye rejection more than 15%. The rejection enhancement for all cases was negligible by increasing driving pressure from 1 to 4 bar. Dyes with low charger were more sensitive to operating pressure than that of dyes with higher charges. All findings supported that acrylic grafted nanomembrane is potentially capable to separate dyes from colored textile effluent.     

Development of light‐induced functionalized asymmetric polysulfone membranes

The introduction of functionality into asymmetric polysulfone membranes has widened their applicability. They are modified with acrylic acid with a light‐induced technique. Fourier transform infrared, contact‐angle, porometry, and atomic force microscopy studies have been carried out to characterize the membranes. The performance of the modified membranes has been investigated with permeation measurements. The salt rejection (NaCl and Na₂SO₄) performance of the modified membranes shows evidence of functionalization on them. The modification of the membranes also develops the retention of small organic molecules (glucose and 2,4‐dichlorophenol). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Ionically crosslinked poly(acrylic acid) membranes. IV. Composite reverse osmosis membranes

Composite reverse osmosis membranes of ionically crosslinked poly(acrylic acid) (PAA) have been prepared. The process consists of coating a porous polysulfone membrane with a thin layer of dilute solution of PAA, drying the thin liquid layer, and ionically crosslinking the PAA in solutions of different salts. The influence of some important preparation parameters on the properties of these membranes was investigated. It was found that all these membranes possessed ion exchange properties and could be ion exchanged; some of them have been found to be suitable for the desalination of low concentration salt solutions. By comparison to cellulose acetate (CA) membranes, higher rejection of phenols may be an interesting property of these membranes.     

Copolymerization of sulfur dioxide with some alkenoic acids

The copolymerization of sulfur dioxide with some alkenoic acids such as acrylic, 3-butenoic, 4-pentenoic, and 10-undecenoic acid was carried out using organic and aqueous media in the presence of (CH₃)₃ COOH/SO₂ redox system. Elemental analysis, IR, and ¹³C-NMR revealed that the copolymers synthesized from the acrylic acid/SO₂ system were of variable composition in organic media, but only polyacrylic acid homopolymer was formed in the presence of water. The other three alkenoic acid/SO₂ systems gave always polysulfone copolymers of alternating structure regardless of the experimental conditions employed. Thermal analysis (TGA and DTA) of selected samples gave T_g in the 73–101°C, range T_m between 160 and 228°C, and the total weight loss in air from 31 to 97%. Flammability decreased as the S:C mole ratio increased. NMR shows that the complexation of SO₂ with the C?C part of all alkenoic acids is low.     

添加剂对聚砜膜结构和性能的影响

通过浸没沉淀相转化法制备聚砜超滤膜,分别以高分子聚乙烯基吡咯烷酮（PVP-K30,PVP-K90）、聚乙二醇（PEG-6000,PEG-20000）和小分子氯化锌（ZnCl2）、丙酸（AS）6种物质作为制备聚砜超滤膜的添加剂,含量均为10%。并对聚砜超滤膜的断面结构、纯水通量、牛血清蛋白（BSA）截留率、孔隙率及平衡水含量等5项性能进行了测试及表征。由断面结构可以看出,PVP-K90作为添加剂时,制得膜的断面完全为海绵状结构,其它添加剂制得膜断面中均有指状孔结构;PVP-K30作为添加剂时制得膜的纯水通量最大;丙酸作为添加剂制得膜的BSA截留率最高;聚乙烯基吡咯烷酮（PVP）和聚乙二醇（PEG）制得膜的平衡水含量及总孔隙率均较高,但闭孔也较多。     

合成丙烯酸催化剂研究进展

对用于合成丙烯酸催化剂进行分类总结,综述丙烯氧化制丙烯酸催化剂和丙烷氧化制丙烯酸催化剂研究进展。丙烯两步氧化法制丙烯酸催化剂应用广泛,催化剂主要为Mo-Bi系和Mo-V系复合氧化物。提出扩大丙烯酸下游产品领域对调节产能扩张的重要性,提高国产丙烯酸催化剂性能、增强工业应用能力、降低生产成本、减少污染物排放和开发新型丙烯酸催化剂及其生产技术是下一步的研究重点。     

Preparation and characterization of proton conducting polysulfone grafted poly(styrene sulfonic acid) polyelectrolyte membranes

The syntheses of series of proton conducting comb copolymer membrane involving polysulfone back bone as main chain and poly(styrene sulfonic acid) (PSSA) being side chain, i.e. polysulfone grafted poly(styrene sulfonic acid) (PSU-g-PSSA) are presented. Chloromethylation of the polysulfone backbone was done by Fridel Craft alkylation reaction. Atom transfer radical polymerization was used for control grafting from the chloromethylated positions. The successful substitution of the chloromethyl group and its grafting with PSSA was characterized by elemental analysis and proton nuclear magnetic resonance. Water uptake, electrochemical properties like ion exchange capacity (IEC) and proton conductivities increase with increase in PSSA contents. Thermal gravimetric analysis (TGA) showed the thermal stability of membranes up to 250 °C. Proton conductivity for maximum amount of grafting is 0.02 S/cm.