聚丙烯微孔膜表面肝素化及其对低密度脂蛋白的吸附特性

为了赋予聚丙烯微孔膜(PPMM)选择性吸附低密度脂蛋白(LDL)的能力,发展了一种有效的PPMM表面共价固定肝素的方法.基于紫外引发丙烯酸的接枝聚合,通过碳二亚胺活化,以乙二胺为间隔臂,将肝素共价固定于PPMM表面,获得表面肝素化的PPMM.ATR-FTIR和XPS分析确证了修饰过程中膜表面基团及化学成分的变化.采用静...     

SURFACE MODIFICATION OF POLYPROPYLENE MICROPOROUS MEMBRANE BY TETHERING POLYPEPTIDES

Two kinds of polypeptides were tethered onto the surface of polypropylene microporous membrane （PPMM） through a ring opening polymerization of L-glutamate N-carboxyanhydride initiated by amino groups which were introduced by ammonia plasma and y-aminopropyl triethanoxysilane treatments. X-ray photoelectron spectroscopy （XPS）, attenuated total reflectance Fourier transform infrared spectroscopy （FT-IR/ATR）, scanning electron microscopy （SEM）, together with water contact angle measurements were used to characterize the modified membranes. XPS analyses and FT-IR/ATR spectra demonstrated that polypeptides are actually grafted onto the membrane surface. The wettability of the membrane surface increases at first and then decreases with the increase in grafting degrees of polypeptide. Platelet adhesion and murine macrophage attachment experiments reveal an enhanced hemocompatibility for the polypeptide modified PPMMs. All these results give evidence that polypeptide grafting can simultaneously improve the hemocompatibility as well as reserve the hydrophobicity for the membrane, which will provide a potential approach to improve the performance of polypropylene hollow fiber microporous membrane used in artificial oxygenator.     

SURFACE MODIFICATION OF MICROPOROUS POLYPROPYLENE MEMBRANES BY GRAFT POLYMERIZATION OF N,N-DIMETHYLAMINOETHYL METHACRYLATE

Surface modification of microporous polypropylene hollow fiber membranes was performed by radical-induced graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA). The influences of temperature, monomer concentration and pre-adsorbed amount of benzoyl peroxide on grafting degree were studied respectively. It was found that the appropriate graft temperature was 75℃, at which the grafting degree was the highest and the hydrolytic decomposition of DMAEMA the lowest. Scanning electron photomicrography and the average pore diameters of the modified membranes demonstrated that part of the micropores on the membrane surface was plugged by the grafted polyDMAEMA chains, especially at high grafting degree. Contact angle and water swelling experiments showed that a moderate grafting degree could improve the hydrophilicity of the membranes. In the range of I 1.3%o-12.0% grafting degree, the water swelling percentage reached its maximum (51.1%) and the contact angle reached its minimum (74 degrees). The bovine serum albumin (BSA) adsorption experiment indicated that the grafted polyDMAEMA had a dual effect on protein adsorption. At the first stage, the BSA adsorption decreased with increasing of DMAEMA grafting degree. As the interaction between BSA and polyDMAEMA on membrane surface increased, the BSA adsorption increased with increasing of DMAEMA grafting degree.     

高分子量级分含量对熔体挤出拉伸法制备聚丙烯微孔膜的影响

通过熔体挤出拉伸法以两种聚丙烯为原料制备微孔膜.通过考察原料分子量数据发现高分子量聚丙烯(PPH)在高分子量级分(重均分子量>106)含量上大于低分子量聚丙烯(F401).PPH的弛豫时间在相同条件下也远大于F401.红外二向光法结果表明,PPH在相同熔体牵伸比下片晶取向度较F401高.相同加工条件下PPH微孔膜片较F401成孔分布更均匀,孔径尺寸也更均匀.2种微孔膜孔隙率都随熔体牵伸比的增加而提高,微孔分布随着熔体牵伸比的提高和片晶取向度的增加而趋于均匀,孔尺寸也随之区域均匀.研究表明,聚合物树脂中高分子量级分含量是影响预制膜中片晶取向度、冷热拉伸成孔分布和尺寸均匀度的重要影响因素.     

添加型聚丙烯大分子表面改性剂PP-g-PEG的制备及其应用

以马来酸酐为桥联剂,通过其与单端羟基聚乙二醇的反应,合成了大分子表面改性剂聚丙烯-聚乙二醇接枝共聚物,探索了反应条件对接枝反应的影响,用IR、NMR、TGA、DSC对接枝物的结构及性能进行研究,并通过共混研究了接枝物对聚丙烯的表面改性效果.结果表明,提高马来酸酐接枝聚丙烯或聚乙二醇的分子量,会阻碍接枝反应的进行,接枝率明显下降;接枝聚乙二醇降低了接枝物的结晶能力;聚丙烯-聚乙二醇接枝共聚物的热稳定性随着聚乙二醇的含量增加及侧链聚乙二醇长度的增加略有下降;聚丙烯-聚乙二醇接枝共聚物组分在共混物中具有明显的向外择优迁移特性,可以作为聚丙烯的添加型表面改性剂使用.     

SURFACE MODIFICATION OF POLYPROPYLENE MICROFIBRE BY PLASMA-INDUCED VAPOR GRAFTING WITH ACRYLIC ACID

The hydrophilicity, dyeing and antistatic ability of polypropylene microfibre (PPMF) wereimproved by plasma-induced vapor grafting with acrylic acid. The effects of plasma discharge time, power,liquid phase acrylic acid temperature and environmental temperatore on grafting yield were investigated. Theexistence of grafted polyacrylic acid (PAA) was verified by ESCA and ATR FT-IR. The morphology ofgrafted PAA was directly observed by SEM. The wicking test shows that the hydrophilicity of modifiedPPMF is greatly enhanced. The dyeability test of modified PPMF was carried out using Dispersion Yellow. Itwas found that the dye uptake ratio is linear to the weight percent of grafting. The antistatic ability wasindicated by specific resistance. The specific resistance of modified PPMF was reduced to 10~6～10~7Ω·cm,thus the antistatic ability was considerably improved.     

SYNTHESIS OF AMPHIPHILIC COMB-SHAPED COPOLYMERS USED FOR SURFACE MODIFICATION OF PVDF MEMBRANES

The synthesis of a novel amphiphilic comb-shaped copolymer consisting of a main chain of styrene-(N-(4- hydroxyphenyl) maleimide)(SHMI) copolymer and poly(ethylene glycol) methyl ether methacrylate(PEGMA) side groups was achieved by atom transfer radical polymerization(ATRP).The amphiphilic copolymers were characterized by ~1H-NMR, Fourier transform infrared(FTIR) spectroscopy and gel permeation chromatography(GPC).From thermogravimetric analysis (TGA),the decomposition temperature of SHMI-g-PEGMA is low...     

表面接枝改性纳米二氧化硅填充聚丙烯的结晶行为

应用差示扫描量热方法研究了纳米二氧化硅 (SiO2 )及其表面接枝改性对聚丙烯 (PP)结晶过程、等温与非等温结晶动力学的影响 ,并研究了上述等温结晶的熔融行为和平衡熔点 .研究发现纳米SiO2 具有明显的异相成核效应 ,能够提高PP的结晶温度、熔融温度、结晶度和结晶速率 ,但降低聚丙烯结晶的完善程度 .粒子的表面接枝处理 ,因改善了粒子与基体的亲和性而有利于粒子成核效应的提高 ,而且此效应尚与粒子的分散相关     

纳米碳酸钙/庚二酸复合成核剂对热致相分离法制备聚丙烯微孔膜的影响

以大豆油/邻苯二甲酸二丁酯(DBP)为混合稀释剂,采用热致相分离法(TIPS)制备聚丙烯(PP)微孔膜.研究了纳米碳酸钙成核剂、纳米碳酸钙/庚二酸复合成核剂对PP/大豆油/DBP(30/42/28,质量比)混合体系中PP结晶、熔融性能和PP微孔膜微观结构的影响.结果表明,单一纳米碳酸钙成核剂加入量为PP的0%~4%(质量百分率)时,PP/DBP/大豆油体系中PP熔融曲线上对应的峰值温度(Tpm)降到150.7~151.3℃,而纯PP的熔融峰值温度为165℃;DSC实验结果还显示加入1%~4%纳米碳酸钙和0.5%庚二酸后,导致PP的熔融曲线上出现了熔融双峰,说明纳米碳酸钙/庚二酸复合成核剂与单一成核剂相比有明显地促进β晶生成的作用,宽角X射线衍射(WAXD)实验进一步证实了β晶的存在.单一纳米碳酸钙成核剂对PP微孔膜的球晶结构和微观孔结构影响不大;加入纳米碳酸钙/庚二酸复合成核剂明显影响PP微孔膜的球晶结构和微观孔结构,其中0.5%庚二酸和1%纳米碳酸钙组成的复合成核剂制得的PP微孔膜的球晶结构明显,微孔膜孔径小且分布均匀;进一步增加纳米碳酸钙用量,PP微孔膜生成了许多细小的边界模糊的不规则结晶,微孔膜孔径不规则且尺寸较大,这与此时PP形成β晶结构有关.     

硬脂酸表面改性碳酸钙粉末的热分析及其表面性质变化

硬脂酸表面改性碳酸钙粉末的热分析及其表面性质变化李新军廖景发＊瞿龙＊吕海波（中南工业大学粉末冶金研究所＊化学系长沙４１００８３）关键词表面改性热分析碳酸钙粉末表面性质硬脂酸中图分类号Ｏ６２３．６１１，Ｏ６４７．２碳酸钙粉末是一种重要的无机化工产品，广...     

等离子体聚合法制备膜蒸馏用疏水微孔复合膜

本文以八氟环丁烷为单体,采用等离子体聚合法将亲水性硝酸纤维素微孔膜改性,制得疏水硝酸纤维素微孔复合膜。所得疏水微孔复合膜可用于膜蒸馏,并具有优良的膜蒸馏性能,其通量达到反渗透水平。利用扫描电镜、X-射线显微分析和XPS等分析手段研究了聚合条件对所得复合膜结构性能的影响.     

盐酸溶液中阴离子表面活性剂在铝表面上的吸附

用失重法研究了盐酸溶液中阴离子表面活性剂十二烷基磺酸钠（ＤＳＡＳＳ），十二烷基苯磺酸钠（ＤＢＳＡＳ）以及十二烷基硫酸钠（ＳＤＳ）在铝表面上的吸附作用，提出这种吸附作用与铝的失重量有关，且符合Ｌａｎｇ－ｍｕｉｒ方程，计算出吸附热，吸附熵和吸附自由能等热力学参数。认为这种吸附主要靠静电作用，根据接触角的变化讨论了阴离子表面活性剂分子在铝表面上的吸附取向。     

SURFACE MODIFICATION OF POLYMERS

The principal objectives and methods of surface modification of polymers are reviewed inthis paper. The methods covered include physical, chemical, mechanical and biological.     

纳米碳酸钙及其表面处理对等规聚丙烯结晶行为的影响

应用差示扫描量热方法研究了不同表面改性碳酸钙纳米粒子对聚丙烯 (PP)等温与非等温结晶动力学的影响 ,并研究了上述各聚丙烯结晶样品的熔融行为和晶型 .研究发现纳米碳酸钙具有明显的成核效应 ,并具有较强的诱导 β 型结晶的能力 ,而且与粒子的表面处理密切相关 .     

纳米微晶纤维素表面改性研究

分别对纳米微晶纤维素(NCC)的表面进行醋酸酯化、羟乙基化和羟丙基化改性,利用FT-IR、TEM、13C-NMR、TGA对改性产物进行表征,研究不同的表面改性方法对纳米微晶纤维素性能的影响.结果表明,利用这几种方法改性后的NCC,经干燥后都可以重新分散在适当的溶剂中,且颗粒粒径没有明显变化,但不同改性产物的热性能有所差异.     

BEHAVIOR OF CHO CELLS ON MODIFIED POLYPROPYLENE BY LOW TEMPERATURE AMMONIA PLASMA

The surface of polypropylene(PP) membrane was modified by low temperature plasma with ammonia.The effect of exposure time was investigated by means of contact angle measurement.The results show that low temperature ammonia plasma treatment can enhance its hydrophilicity.Chinese hamster ovary(CHO)cells attachment on the modified membrane was enhanced and the growth rate on the membrane was faster than unmodified one.     

聚苯乙烯大单体与丙烯酸酯接枝共聚物对聚苯乙烯表面的改性研究

研究了由大单体技术合成的侧链为聚苯乙烯、骨架由丙烯酸丁酯或甲基丙烯酸羟乙酯/丙烯酸丁酯组成的接枝共聚物对聚苯乙烯的表面改性效果(试样浇注于玻璃纸上成膜)。发现仅添加0.5wt％的接枝共聚物就可完全改变聚苯乙烯膜两面的临界表面张力γ-c与表面能中的色散力部份γ_s~D,少量添加的接枝共聚物在改性聚苯乙烯膜的两面呈现出明显的表面富集现象。虽然两类接枝共聚物的极性有较大的差异,但改性聚苯乙烯成膜后的自由表面均显示出与聚丙烯酸丁酯相同的低表面能(γ_s~D=37×10~(-3)牛顿·米~(-1)),而添加三元接枝共聚物的改性膜与玻璃纸接触的表面却具有高于聚苯乙烯的表面能|(γ_s~D=54×10(-3)牛顿·米~(-1))。这种改性膜的两面具有不同的表面能是由于接枝共聚物中不同的组分在膜的两面富集所致,已通过ESCA的表面测试结果证实,并与按Gibbs吸附式的计算值相符。     

BEHAVIOR OF CHO CELLS ON MODIFIED POLYPROPYLENE BY LOW TEMPERATURE AMMONIA PLASMA

1. INTRODUCTION Bioreactors using membranes as substrates of cell cultures have become widely used for hybrid liver support systems [1]. For enhancing and prolonging the metabolism of the bioreactors, cytocompatible membranes are necessary because the cell culture is closely affected by the substrate surface. Surface factors considered to be important in cell culture are the concentration of ionic groups, the nature of polar and non-polar groups and the hydrophilic-hydrophobic balance [2].…     

INTERACTION BETWEEN THE SURFACE GLYCOSYLATED POLYPROPYLENE MEMBRANE AND LECTIN

A glycopolymer bearing glucose residues was tethered onto the surface of polypropylene microporous membrane by UV-induced graft polymerization ofα-allyl glucoside.Concanavalin A (Con A),a glucose recognizing lectin,could be specifically adsorbed to the membrane surface.On the other hand,the membrane surface showed no recognition ability to another lectin peanut agglutinin.Moreover,the recognition complex between the glycosylated membrane surface and Con A could be inhibited by glucose and mannose solutio...     

不同金属盐改性对硅胶的水蒸气吸附性能影响

用不同的金属盐溶液对中孔硅胶进行了改性,并进行了吸附水蒸气动力学实验.讨论了改性硅胶的吸湿性与离子半径之间的关系及吸附速率与平均孔径的关系.实验结果表明:(1) CaCl2,LiCl,MgCl2,ZnCl2改性硅胶,可以使硅胶的吸湿性能明显增加.其中用CaCl2改性的硅胶的吸湿量最大,其平衡吸湿量是未改性硅胶的3倍;(2) 用CaCl2溶液改性的中孔硅胶其吸湿量已接近微孔硅胶的吸湿量,但其吸附速率明显大于微孔硅胶的吸附速率;(3) 用CaCl2和ZnCl2的混合溶液改性硅胶对其吸湿量的提高没有明显效果.