聚（乙烯—醋酸乙烯）／聚苯乙烯复合乳胶膜的研究

采用种子乳液聚合法制得的聚（乙烯－醋酸乙烯）／聚苯乙烯（ＥＶＡ／ＰＳｔ）复合乳胶膜具有“感温”特性。研究了不同的组分配比、不同的热处理温度以及不同的引发剂对ＥＶＡ／ＰＳｔ复合乳胶膜热处理前后性能的影响，探讨了复合乳胶膜的性能与其相态结构的关系。     

HDP—PVC／ABS合金材料的研究

研究了高聚合度聚氯乙烯（ＨＤＰ－ＰＶＣ）／ＡＢＳ二元体系力学性能以及添加第三组分对合金材料力学性能的影响。结果表明：ＨＤＰ－ＰＶＣ／ＡＢＳ配比为１００／２５时,共混物的综合性能好,体系能形成较完善的海岛结构;ＨＤＰ－ＰＶＣ／ＡＢＳ／ＭＢＳ体系中,ＭＢＳ能改善多元体系的界面性能,提高合金材料的综合性能;ＨＤＰ－ＰＶＣ／ＡＢＳ／ＣＰＥ体系中,ＣＰＥ能使形成网状结构和海岛结构共存的合金体系,提高合金材料     

反应挤了HDPE／PET共混合金结构与性能研究

采用ＤＳＣ、ＷＡＸＤ、ＳＥＭ及ＴＧＡ等方法研究了ＨＤＰＥ／ＰＥＴ共混合金在增溶剂Ｅ／ＶＡＣ或Ｅ／ＡＡ作用下的结晶性、形态结构及热稳定性。结果表明，Ｅ／ＶＡＣ或Ｅ／ＡＡ的加入，使ＨＤＰＥ／ＰＥＴ体系中ＨＤＰＥ组分的熔融热焓降低，结晶度下降，但熔融峰位置和晶胞基本保持不变；从ＳＥＭ照片可以观察到Ｅ／ＶＡＣ、Ｅ／ＡＡ对共混体系具有一定的增容作用，Ｅ／ＡＡ和效果优于Ｅ／ＶＡＣ；共混体系的热稳定性随Ｅ／ＶＡ     

CPE对PVC／SBR共混体系增容作用的研究

通过微观冲击试验、动态力学分析（ＤＭＡ）、扫描电镜（ＳＥＭ）和透射电镜（ＴＥＭ）观察，研究了氯化聚乙烯（ＣＰＥ）增容的ＰＶＣ／丁苯橡胶（ＳＢＲ）共混物的性能与形态结构之间的关系。试验结果表明ＣＰＥ对ＰＶＣ／ＳＢＲ共混体系有良好的增容作用。     

FPE和PVC的相互作用及其对PVC/CPE/FPE合金性能和形态结构的影响

用ＦＴＩＲ光谱证实了ＰＶＣ与ＰＥ８ＤＢＭ（简称ＦＰＥ）之间存在着氢键和偶极偶极的作用,其中以氢键作用为主。测定了ＰＶＣ／ＣＰＥ／ＰＥ和ＰＶＣ／ＣＰＥ／ＦＰＥ合金的力学性能,用ＤＳＣ、相衬显微镜及ＳＥＭ表征了这两个体系的微观形态结构,研究了共混物中异种分子间的相互作用对合金性能与形态结构的影响     

PP／EVA－15共混物的研究

应用ＳＥＭ和力学性能测试研究了ＰＰ／ＥＶＡ－１５共混物原料配比、工艺条件和微观结构形态对材料性能的影响，对共混物的增韧机理进行了分析。与弹性体（ＥＰＤＭ）改性ＰＰ所作的比较显示，ＥＶＡ－１５对ＰＰ有良好的改性效果，其综合性能优于ＰＰ／ＥＰＤＭ共混物。     

PS对PVC＼CPE体系加工性能及凝胶度的影响

采用Ｂｒａｂｅｎｄｅｒ塑化仪，双辊开炼机探讨了ＰＳ树脂对ＰＶＣ／ＣＰＥ体系加工性能及力学性能的影响。利用零长毛细管流变仪测量了ＰＶＣ／ＣＰＥ／ＰＳ共混体凝胶度与加工温度，力学性能的关系。结果表明：填加少量ＰＳ树脂能缩短ＰＶＣ／ＣＰＥ体系的塑化时间，改善其塑化性能，提高基体的流动性，ＰＳ填加适量时，基体的力学笥能有所改善。当加工温度为１８０℃时，体系的凝胶含量为９０－９４％，此时综合性能最佳。     

重质芳烃油在PVC/SBR共混型热塑性弹性体中的应用研究

用重质芳烃油代替部分ＤＯＰ作增塑剂，通过动态全硫化法制成了ＰＶＣ／ＳＢＲ共混型热塑性弹性体（ＴＰＥ）。试验了不同增塑剂的品种和用量对共混物性能的影响，结果表明：当ＰＶＣ／ＳＢＲ的配比为５５／４５、重质芳烃油与ＤＯＰ的并用比为３／２时，共混物的力学性能和工艺性能均可满足使用要求。     

BR／PVC／SBS三元橡塑热弹性弹性体的配方设计及工艺研究

介绍了用动态硫化法挤出制备丁腈橡胶／聚氯乙烯／苯乙烯－丁二烯－苯乙烯共聚物（ＢＲ／ＰＶＣ／ＳＢＳ）三元橡塑热塑性弹性体,并采用ＤＳＣ、ＳＥＭ、布拉本达流变仪和力学方法研究其工艺条件、配方组成与结构、性能的关系。本研究的ＢＲ／ＰＶＣ／ＳＢＳ三元橡胶热塑性弹性体综合了ＰＶＣ、ＳＢＳ、ＢＲ三者的优点,可用于高档鞋料。     

BR/PVC/SBS三元橡塑热塑性弹性体的配方设计及工艺研究

介绍了用动态硫化法挤出制备丁腈橡胶／聚氯乙烯／苯乙烯丁二烯苯乙烯共聚物（ＢＲ／ＰＶＣ／ＳＢＳ）三元橡塑热塑性弹性体,并采用ＤＳＣ、ＳＥＭ、布拉本达流变仪和力学方法研究其工艺条件、配方组成与结构、性能的关系。本研究的ＢＲ／ＰＶＣ／ＳＢＳ三元橡塑热塑性弹性体综合了ＰＶＣ、ＳＢＳ、ＢＲ三者的优点,可用于高档鞋料。     

EFFECT OF POLYVINYLPYRROLIDONE ADDITIVE ON THE PORE SIZE AND THE PORE SIZE DISTRIBUTION OF POLYETHERSULFONE (VICTREX) MEMBRANES

Investigations were made on the effect of the presence of polyvinylpyrrolidone (PVP) additive in the casting solution on the performance of polyethersulfone (PES) ultrafiltration membranes in the range of PVP/PEs weight ratio below 0.5. It was further attempted to investigate the effect of PVP additive on the size of PES polymer in the casting solution and the pore size and the pore size distribution of PES membranes. It was found that the presence of PVP additive decreases both the polymer size and the membrane pore size. Discussions were made on the mechanism of the formation of the pore based on the correlation between the polymer size and the pore size.     

聚乙烯吡咯烷酮对聚醚砜膜结构和性能的影响

以聚醚砜为膜材料,聚乙烯吡咯烷酮（PVP）为添加剂,N,N-二甲基乙酰胺为溶剂,采用相转化法制备了聚醚砜超滤膜。通过制膜液粘度、膜的孔隙率、表面接触角、机械性能以及对牛血清蛋白分离性能的测试和扫描电镜（SEM）对膜孔结构的观察,研究了PVP的添加量对聚醚砜制膜液粘度及其膜结构和性能的影响。结果表明,PVP的添加提高了膜的亲水性和制膜液的粘度,但膜的抗拉强度有所降低;膜的水通量随着PVP含量的增加先升高后降低,在5%时最大水通量是508.33L/（m^2·h）,而此时牛蛋白截留率最小为66.27%;SEM观察的结果是膜的断面上部形成指状孔结构,下部形成海绵状孔结构,当PVP含量为5%时膜有斜指状孔结构,且指状孔也逐渐延伸到膜的底部,其壁为稀疏的海绵状孔结构。     

Polysulfone Membranes. III. Performance Evaluation of Polyethersulfone—PVP Membranes

Abstract

The performance of membranes produced from casting solutions consisting of polyethersulfone (PES), poly-(N-vinyl-pyrrolidone) (PVP), and N-methyl-2-pyrrolidinone (NMP) were systematically studied. Zero-shear casting solution viscosities for these polymer solutions were determined as a function of PES and PVP concentrations. Ultrafiltration membranes were then cast using the phase inversion technique and characterized by separation experiments using polyethylene glycols of various molecular weights as test solutes. A pore flow model was fitted to the resulting separation data to provide estimates of the average pore radius and membrane porosity. These parameters were used to compare laboratory results for this membrane casting solution system with performance data for commercially available polyethersulfone membranes.     

Effects of coagulation bath temperature and polyvinylpyrrolidone content on flat sheet asymmetric polyethersulfone membranes

In this study, effects of coagulation bath temperature (CBT) and polyvinylpyrrolidone (PVP K15) concentration as a pore former hydrophilic additive on morphology and performance of asymmetric polyethersulfone (PES) membranes were investigated. The membranes were prepared from a PES/ethanol/NMP system via phase inversion induced by immersion precipitation in a water coagulation bath. The morphology of prepared membranes was studied by scanning electron microscopy (SEM), contact angle measurements, and mechanical property measurements. Permeation performance of the prepared membranes was studied by separation experiments using pure water and bovine serum albumin (BSA) solution as feed. The obtained results indicate that addition of PVP in the casting solution enhances pure water permeation flux and BSA solution permeation flux while reducing protein rejection. Increasing CBT results in macrovoid formation in the membrane structure and increases the membrane permeability and decreases the protein rejection. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

Development of novel surface modified phase inversion membranes having hydrophobic surface-modifying macromolecule (nSMM) for vacuum membrane distillation

Eleven PES membranes, into which newly synthesized surface-modifying macromolecule (nSMM) was incorporated, were prepared by using the ‘phase inversion technique’ with different preparation conditions to find the effects of membrane casting parameters on the characteristics and performances of the surface modified PES membranes. The membranes so prepared were characterized by solute separation data from ultrafiltration experiments. The results showed that the mean pore size as well as the surface hydrophobicity increased with an increase in evaporation time for the casting solution blended with nSMM (without PVP). When PVP was added into the casting solution, the mean pore size as well as the contact angle decreased while the pure water permeation flux increased. The surface hydrophobicity decreased with an increase in gelation bath temperature.Four membranes were further prepared and subjected to vacuum membrane distillation (VMD). They were characterized by different analytical instruments and pure water permeation test before being used to VMD. The results showed that a distinctive surface layer was formed in nSMM blended PES membranes. It was also found that nSMM blended PES membranes were sufficiently hydrophobic and porous to be used for the separation of an ethanol/water mixture.     

Effects of casting solution composition on performance of poly(ether sulfone) membrane

Flat-type poly(ether sulfone) (PES) membranes for ultrafiltration were prepared by the traditional phase-inversion technique. The effects of the concentration of PES and the combination of two solvents, dichloromethane (DCM) and N-methyl-2-pyrrolidone (NMP), with differences in volatility and solvating power on membrane performance were examined in terms of pure water flux (PWF) and solute rejection (SR) against poly(ethylene glycol) (PEG, MW 20,000). Changing the thermodynamic quality of PES/NMP casting solution by combining DCM, a volatile and weak solvent, affected the PWF of the resulting membrane. The SR of PES/DCM–NMP membrane, however, was more likely dependent upon the effect of evaporating the volatile solvent from the casting solution/air interface rather than the effect of changing the thermodynamic quality of the casting solution. Combining DCM in PES/NMP casting solution transformed the fingerlike macrovoids of PES/NMP membrane prepared without DCM into the isolated macrovoids. PES/DCM–NMP membrane prepared with PVP, a water soluble poreforming agent, showed an increased PWF while maintaining SR of over 90%, even under the reduced feeding pressure of 1 kg/cm². It is necessary to measure molecular weight cutoff of membrane for demonstrating the potential of PVP for improving the membrane permeability without losing the selectivity.© 1996 John Wiley & Sons, Inc.     

Effect of polyvinylpyrrolidone on morphology and performance of hemodialysis membranes prepared from polyether sulfone

Flat‐sheet hemodialysis membranes were prepared by phase inversion technique using polyether sulfone (PES) dissolved in dimethylacetamide (DMAc) with and without the addition of polyvinylpyrrolidone (PVP). The effect of the composition of the casting solution on membrane morphology and performance were investigated. The performances of membranes were elucidated on the basis of removal of uremic toxins (urea, uric acid, and creatinine) from human blood serum. The membrane prepared from 12 wt % PES with 2.8 wt % PVP demonstrated better performance compared to the other compositions. The membrane performance is a consequence of membrane morphology. Membranes with channel‐like or long finger‐like structures provide superior removal efficiencies. If the morphology turns to a sponge structure, the effectiveness is diminished. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3804–3813, 2004     

Concentration of gelatin solution with polyethersulfone ultrafiltration membranes

In this work, polyethersulfone (PES) flat sheet ultrafiltration (UF) membranes were prepared by immersion precipitation phase inversion process with polyvinylpyrrolidone (PVP 30K) and acetone as additives. The best preparation condition for PES membranes with high water flux and rejection (to BSA) was decided. It was found that the optimal composition of the polymer casting solution was: 16 wt% (PES), 2 wt% (PVP 30K), and 1 wt% (acetone). Pure water flux of the membrane prepared at this condition reached to 373 L/m² h at 0.1 MPa, and the rejection to BSA was 91%. Compared with other reports, the rejection was slightly low but the flux of the PES membrane was high. When the membrane was used to concentrate gelatin solutions, the rejection value was over 75%. It was found that increasing the feed temperature and transmembrane pressure enhanced the permeation flux, but the rejection decreased slightly. However, increasing the cross-flow velocity of the feed solution simultaneously increased both the permeation flux and the rejection.     

The Effect of Polyethersulfone Concentration on Flat and Hollow Fiber Membrane Performance

Abstract

Flat and hollow fiber (HF) membranes are made in order to determine the effect of the polyethersulfone (PES) concentration in the precursor film-casting solution on resultant flat and hollow fiber membrane performance. The additive polyvinyl-pyrrolidone (PVP) is included in the film-casting solution to ensure that membranes can be made over wide variations in the PES polymer concentration. In general, membrane permeability decreases and solute separation ability increases as the PES concentration increases. However, for both flat and HF membranes, performance is strongly dependent on whether the PES concentration is above or below the critical value. Flux greatly decreases and solute-separation ability increases when the critical PES concentration is surpassed. Membrane performance is generally optimized when the PES concentration is at the critical value.     

Effect of additives concentration on performance of cellulose acetate and polyethersulfone blend membranes

Asymmetric micro porous membranes have been prepared successfully from blending of cellulose acetate (CA) and polyethersulfone (PES) by the phase inversion method with N, N-dimethylformamide (DMF) as solvent. Two additives were selected in this study, including polyethylene glycol 600 (PEG 600) and polyvinylpyrrolidone (PVP). The effects of concentration of additives on CA/PES blend membrane performance and cross-section morphology were investigated in detail. CA/PES membranes were compared with CA/PES/PEG and CA/PES/PVP membranes in the performance such as pure water flux, membrane resistance, porosity and cross-section morphology. The resulting blend membranes were also carried out the rejection and permeate flux of Egg Albumin (EA) proteins with molecular weight of 45 Da. The membranes thus obtained with an additive concentration of 5 wt% of both PEG and PVP exhibited superior properties than the 80/20% blend composition of CA and PES membranes. The permeate flux of protein was increased from 44 to 134 lm² h with increase in concentrations of both PVP and PEG in 80/20% blend composition of CA and PES membranes. Cross-sectional images from scanning electron microscopy showed larger macropores in the bottom layer of the membranes with increasing additives content. Observations from scanning electron microscopy provided qualitative evidence for the trends obtained for permeability and porosity results.