Effect of polyethylene glycol molecular weights and concentrations on polyethersulfone hollow fiber ultrafiltration membranes

Polyethersulfone (PES) hollow‐fiber membranes were fabricated using poly(ethyleneglycol) (PEG) with different molecular weights (MW = PEG200, PEG600, PEG2000, PEG6000, and PEG10000) and poly(vinyl pyrrolidone) PVP40000 as additives and N‐methyl‐2‐pyrrolidone (NMP) as a solvent. Asymmetric hollow‐fiber membranes were spun by a wet phase‐inversion method from 25 wt % solids of 20 : 5 : 75 (weight ratio) PES/PEG/NMP or 18 : 7 : 75 of PES/(PEG600 + PVP40000)/NMP solutions, whereas both the bore fluid and the external coagulant were water. Effects of PEG molecular weights and PEG600 concentrations in the dope solution on separation properties, morphology, and mechanical properties of PES hollow‐fiber membranes were investigated. The membrane structures of PES hollow‐fiber membranes including cross section, external surface, and internal surface were characterized by scanning electron microscopy and the mechanical properties of PES hollow‐fiber membranes were discussed. Bovine serum albumin (BSA, MW 67,000), chicken egg albumin (CEA, MW 45,000), and lysozyme (MW 14,400) were used for the measurement of rejection. It was found that with an increase of PEG molecular weights from 200 to 10,000 in the dope solution, membrane structures were changed from double‐layer fingerlike structure to voids in the shape of spheres or ellipsoids; moreover, there were crack phenomena on the internal surfaces and external surfaces of PES hollow‐fiber membranes, pure water permeation fluxes increased from 22.0 to 64.0 L m^?2 h^?1 bar^?1, rejections of three protein for PES/PEG hollow‐fiber membranes were not significant, and changes in mechanical properties were decreased. Besides, with a decrease of PEG600 concentrations in the dope solution, permeation flux and elongation at break decreased, whereas the addition of PVP40000 in the dope solution resulted in more smooth surfaces (internal or external) of PES/(PEG600 + PVP40000) hollow‐fiber membranes than those of PES/PEG hollow‐fiber membranes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3398–3407, 2004     

Electrosprayed porous microspheres for the removal of endocrine disruptors

Polyethersulfone (PES) porous microspheres were prepared via electrospraying technique, and then were used for the removal of endocrine disrupters from aqueous solutions. The surface and the internal structures of electrosprayed microspheres were characterized by scanning electron microscopy (SEM) and the results showed that they were porous. The electrosprayed porous PES microspheres can remove biphenyl A and biphenyl effectively. At the same time, they showed larger adsorption capacity and fast kinetics of uptaking target species than PES injected spheres reported in the earlier publications. The hydrophilicity and porosity of electrosprayed microspheres can be controlled by changing the amount of hydrophilic polyethylene glycol (PEG), which influences the adsorption properties of the microspheres. The results showed that electrosprayed porous PES microspheres have the potential to be used in the environmental application. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation of polyethersulfone/sulfonated polyethersulfonephenylethane microspheres and its application for the adsorption of bisphenol A

A novel kind of sulfonated polyethersulfonephenylethane (SPESPE) was successfully synthesized firstly in this work. Then the SPESPE was introduced in polyethersulfone (PES) microspheres prepared by the electrospraying technique. The microspheres were applied to adsorbing bisphenol A (BPA) from its aqueous solution. Compared with the PES microspheres, the adsorption capacity of PES/SPESPE microspheres for BPA was increased significantly. Furthermore, the adsorption capacity of PES/SPESPE microspheres was enhanced by increasing the amounts of SPESPE in the microspheres. The pH of solution had influence on the adsorption capacity of PES/SPESPE microspheres. The kinetic data of adsorption were found to follow pseudo‐second‐order model. The Freundlich isotherm model was suitable to describe the equilibrium adsorption data. The microspheres also showed excellent regeneration and reuse ability. These results indicated that the PES/SPESPE microspheres have the potential to be used in environmental application. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43066.     

Atomic layer deposition of polyimide on microporous polyethersulfone membranes for enhanced and tunable performances

Atomic layer deposition (ALD) of polyimide (PI) is explored to tune the separation properties of microporous polyethersulfone (PES) membranes and also to improve their mechanic and thermal stability. Conformal and uniform thin layers of PI are deposited along the pore wall throughout the entire PES membrane instead of forming a top layer merely on the membrane surface. With increasing ALD cycles, the pore size of the PES membrane is progressively reduced, leading to increased retention. The permeation is correspondingly decreased but its drop is less pronounced than the increase of retention. For example, the retention to 23‐nm silica nanospheres is significantly increased from nearly zero to 60% after 3000 ALD cycles, whereas the water flux is moderately decreased by 54%. Moreover, ALD of PI evidently enhances the mechanical strength and thermal resistance of the PES membrane as PI tightly wraps the skeleton of the membrane. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3614–3622, 2014     

Development of polylactide microspheres for protein encapsulation and delivery

The development of injectable microparticles for protein delivery is a major challenge. We demonstrated the possibility of entrapping human serum albumin (HSA) and thrombin (Thr) in poly(ethylene glycol) (PEG)‐coated, monodisperse, biodegradable microspheres with a mean diameter of about 10 μm. In our earlier studies, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis was used to characterize the surface of PEG‐coated, taxol‐loaded poly(lactic acid) (PLA) microspheres. An analysis by DRIFTS revealed that PEG was incorporated well on the PLA microsphere surface. An emulsion of protein (in water) and PLA dissolved in an acetone–dichloromethane (or acetone–chloroform) mixture were poured into an aqueous solution of PEG [or poly(vinyl alcohol) (PVA)] with stirring with a high‐speed homogenizer for the formation of microparticles. HSA recovery in microspheres ranged from 13 to 40%, depending on the solvent and emulsification systems used for the preparation. PLA dissolved in a dichloromethane/acetone system and albumin loaded via a PEG emulsification solution (PLA–PEG–HSA) showed maximum drug recovery (39.5%) and drug content (9.9%). Scanning electron microscopy revealed that PEG‐coated microspheres had less surface micropores than PVA‐based preparations. The drug‐release behavior of microspheres suspended in phosphate‐buffered saline exhibited a biphasic pattern. An initial burst release (30%) followed by a constant slow release for 20 days was observed for HSA and Thr from PLA–PEG microspheres. PEG‐coated PLA microspheres show great potential for protein‐based drug delivery. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1285–1295, 2002     

Synthesis and characterization of new biodegradable comb‐dendritic triblock copolymers

A series of well‐defined dumbbell‐shaped triblock copolymers consisting of linear poly(ethylene glycol) (PEG) and comb‐like poly(ε‐caprolactone) (PCL) with varied PCL arm lengths have been synthesized via the sequential preparation of different generation terminal dendronized PEG and ring‐opening polymerization of ε‐caprolactone. The copolymers were characterized using Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopy and gel permeation chromatography. Differential scanning calorimetry was performed to measure the glass transition temperature, melting point and degree of crystallinity and the PEG segment and PCL segment crystallization temperatures. The crystallization of the copolymers was also studied using X‐ray diffraction. The dumbbell‐shaped copolymers were further used to construct microspheres using a double emulsion method. Scanning electron microscopy and dynamic light scattering results showed the size of the microspheres was about 2 to 4 µm and the size distribution was quite narrow. Copyright © 2012 Society of Chemical Industry     

Preparation of collagen‐immobilized poly(ethylene glycol)/poly(2‐hydroxyethyl methacrylate) interpenetrating network hydrogels for potential application of artificial cornea

To enhance the mechanical strength of poly(ethylene glycol)(PEG) gels and to provide functional groups for surface modification, we prepared interpenetrating (IPN) hydrogels by incorporating poly(2‐hydroxyethyl methacrylate)(PHEMA) inside PEG hydrogels. Formation of IPN hydrogels was confirmed by measuring the weight percent gain of the hydrogels after incorporation of PHEMA, as well as by ATR/FTIR analysis. Synthesis of IPN hydrogels with a high PHEMA content resulted in optically transparent and extensively crosslinked hydrogels with a lower water content and a 6 ～ 8‐fold improvement in mechanical properties than PEG hydrogels. Incorporation of less than 90 wt % PHEMA resulted in opaque hydrogels due to phase separation between water and PHEMA. To overcome the poor cell adhesion properties of the IPN hydrogels, collagen was covalently grafted to the surface of IPN hydrogels via carbamate linkages to hydroxyl groups in PHEMA. Resultant IPN hydrogels were proven to be noncytotoxic and cell adhesion study revealed that collagen immobilization resulted in a significant improvement of cell adhesion and spreading on the IPN hydrogel surfaces. The resultant IPN hydrogels were noncytotoxic, and a cell adhesion study revealed that collagen immobilization improved cell adhesion and spreading on the IPN hydrogel surfaces significantly. These results indicate that PEG/PHEMA IPN hydrogels are highly promising biomaterials that can be used in artificial corneas and a variety of other load‐bearing tissue engineering applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Primary study of novel poly(acrylic sodium)/poly(ether sulfone) composite ultrafiltration membranes (I) the preparation of composite membrane

The poly(acrylic sodium) (PAS)/poly(ether sulfone) (PES) composite ultrafiltration membranes were prepared by coating PAS membrane solution on PES support membrane. The effects of substrate membrane, the composition of PAS solution such as PAS concentration, the choice of the solvent and the additive, and the thickness of PAS active layer on the performance of the composite membranes were extensively investigated. The experimental results have indicated the optimal PAS/PES composite membranes, containing a PES substrate with MWCO of 70,000, together with a PAS top layer having a thickness of about 20 μm, were tested at room temperature and under the pressure of 0.6 MPa with the mass concentration of 0.005 g/L poly(ethylene glycol) (PEG) (Mw = 1000 g/mol) solution, a flux of 32.6 L/(m² h) and a rejection of 92.2% were obtained, which are superior to those of the common commercial membranes reported.     

The influence of membrane formation parameters on structural morphology and performance of PES/PDMS composite membrane for gas separation

In this study, influence of membrane preparation parameters on structural morphology and performance of polyethersulfone/polydimethylsiloxane (PES/PDMS) composite membrane was investigated for gas separation. Asymmetric PES flat sheet membranes were composed by phase inversion method and used as supports. PES composite membranes were fabricated by coating silicone rubber as selective layer on the top surface of support. Effects of different concentrations of PES and PDMS, solvent type, and support thickness on membrane performance were investigated for separation of oxygen from nitrogen. The optimized superior membrane was further modified using polyvinylidenfluoride, methanol and ethanol as additives in PES solutions and/or in water coagulation bath to promote the membrane capability. The results showed that addition of ethanol and methanol in cast solution and coagulation bath can greatly affect the morphology and hence the performance of the prepared membranes. The permeance changes have the contrary trend with solubility parameter difference between solvent and nonsolvent mixture, for instance when this parameter difference was lowest, higher permeance was obtained. Support and coating polymer concentration can control the permeance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Cytotoxicity and hemocompatibility of a family of novel MeO‐PEG‐poly (D,L‐lactic‐co‐glycolic acid)‐PEG‐OMe triblock copolymer nanoparticles

A family of newly synthesized monomethoxy (polyethylene glycol)‐poly (D ,L ‐lactic glycolic acid)‐ monomethoxy(polyethylene glycol) (MeO‐PEG‐poly (D ,L ‐lactic‐co‐glycolic acid)‐PEG‐OMe, PELGE) biodegradable polymers are candidates for intravenous nanoparticle drug, because of their merits of biocompatibility and blood compatibility, and their capability of escaping from the endothelium system (RES) and adsorbing proteins. In the current research, relationships between composition, cytotoxicity, and hemocompatibility of a series of blank PELGE nanoparticles were investigated. Cytotoxicity on Chang cell lines was investigated using the methyl thiazolyl tetrazolium (MTT) assay. Human and rabbit blood were used in studies of red blood cell hemolysis, whole blood clotting time, plasma recalcification profiles, and red blood cell form and appearance in whole blood. The results suggested that the molecular weight of PEG used in the synthesis of polymers influenced their characteristics. Generally, as the molecular weight of PEG increased, increased cytotoxicity and hemocompatibility were observed. The RGR (relative growth rate) of PELGE nanoparticles synthesized with PEG 550 was above 70%, while that of PELGE nanoparticles synthesized with PEG 750 and PEG 2000 was in the range of 55–105% and 36–87% respectively. For PELGE nanoparticles synthesized with PEG 550, most hemolysis values were in the range of 1–3%, while for PELGE nanoparticles synthesized with PEG 750 and PEG 2000 hemolysis values were 1–2% and below 2%, respectively. None of the nanoparticles caused changes in red blood cell form or appearance. Based on the results, 12 kinds of PELGE were chosen for further studies. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 2933–2944, 2009     

Effect of hypochlorite treatment on performance of hollow fiber membrane prepared from polyethersulfone/N‐methyl‐2‐pyrrolidone/tetronic 1307 solution

Polyethersulfone (PES) hollow fiber membrane was prepared by blending with nonionic surfactant Tetronic 1307 to improve its hydrophilicity. The membranes were posttreated by hypochlorite solution of 10, 100, 500, and 2000 ppm. The effect of hypochlorite treatment on the performance of PES membrane was investigated. Experimental results showed that the water permeability of treated membrane was two to three times higher than that of untreated membrane in case of blend membrane prepared from PES/N‐methyl‐2‐pyrrolidone (NMP)/Tetronic 1307 solution. On the other hand, hypochlorite treatment has no effect on water permeability of the membrane prepared from PES/NMP solution. Elemental analysis and ATR–FTIR measurement results indicated that hypochlorite treatment led to decomposition and leaching out of Tetronic 1307 component from the membrane. The change of membrane surface structure by the hypochlorite treatment was confirmed by atomic force microscopy measurement. The hypochlorite treatment brought about no significant impact on the mechanical property of the membranes. This indicated that the hypochlorite treatment of PES membrane prepared with surfactant was a useful way to improve the water permeability without the decrease of membrane strength. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

PLA/chain‐extended PEG blends with improved ductility

Melt blending of polylactic acid (PLA) and a chain‐extended polyethylene glycol (CE‐PEG) have been performed in an effort to toughen the PLA without significant loss of modulus and ultimate tensile strength. The chain‐extended PEG was prepared with melt condensation of a low molecular weight PEG and 4,4′‐methylenebis(phenylisocyanate) (MDI) for enhancement of the molecular weight of PEG. The thermal and mechanical properties, miscibility and phase morphologies of blends were investigated. By using thermal and fracture surface analysis, the blends were found to be a partially miscible system with shifted glass transition temperatures. The addition of CE‐PEG leads to slight decrease in tensile strength and modulus, while the elongation at break is characterized by an important increase (540%), compared with neat PLA and PLA/PEG (low molecular weight PEG, M_n = 35,000). The relative ductility of PLA/CE‐PEG is 40 times higher than that of neat PLA. The brittle fracture of neat PLA was transformed into a ductile fracture by the addition of CE‐PEG. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Sulfonated poly(ether sulfone)‐based catalyst binder for a proton‐exchange membrane fuel cell

Sulfonated poly(ether sulfone) copolymer (PES 60) and its partially fluorinated analogue (F‐PES 60) were synthesized via the nucleophilic aromatic polycondensation of commercially available monomers to make a polymer electrolyte membrane and a binding material in the electrodes of a membrane–electrode assembly (MEA). PES 60 and F‐PES 60 showed proton conductivities of 0.091 and 0.094 S/cm, respectively, in water at room temperature. The copolymer was dissolved in the mixture of alcohol and water to get a 1 wt % binder solution. A catalyst slurry was prepared with the copolymer solution and sprayed on the copolymer (PES 60 or F‐PES 60) membrane to obtain a MEA. Both PES 60 and F‐PES 60 based MEAs were fabricated with different amounts of their binder in the electrodes to examine the effect of the copolymer binder in the catalyst layer on the fuel cell performance. The MEA with 2 wt % copolymer binder in the electrodes showed the best fuel cell performance. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Hydrophilic microporous PES membranes prepared by PES/PEG/DMAc casting solutions

Microporous poly(ether sulfones) (PES) membranes were prepared via phase inversion using poly (ethylene glycol) (PEG) as additive and N,N‐dimethylacetamide (DMAc) as solvent. Thermodynamic of the casting solutions was studied by coagulation value while precipitation rate was observed by light transmittance measurement. It was found that casting solution with PEG200 as additive was thermodynamically less stable than those with PEG400 and PEG600 as additive and easier to cause phase separation in exposure time. With the increase of PEG200 concentration, the casting solution became thermodynamically less stable and easier to cause phase separation in exposure time, but precipitation rate during immersion precipitation decreased because of the increased viscosities. ATR‐FTIR spectra and TGA curves showed that the membranes prepared using PEG200 as additive had less PEG residual than those of PEG400 and PEG600, but it showed better permeation performance than that prepared using PEG400 and PEG600 as additive. With the increase of PEG200 concentration from 30 to 70 wt %, the cross section structure changed from macrovoid to sponge‐like, micropores with a mean pore size around 0.1 μm began to form on the top surface. When the PEG200 concentration is 60 wt %, the pure water flux was 1845 L m^?2 h^?1 bar^?1, which is the highest value. As the PEG200 concentration increased from 30 to 60 wt %, the contact angles decreased from 82.1° to 58.2°. As the addition amount of PEG200 increased, the residual PEG made the prepared membranes more hydrophilic. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation of hollow poly(imino ether ketone) microspheres by microliquid technique

1, 4‐bis (4‐amiophenoxy) benzene and 1, 4‐Bis (4‐bromobenzoyl) benzene as monomers, poly(imino ether ketone) (PIEK) was synthesized via palladium‐catalyzed aryl amination reaction. Based on the good chemical and physical properties, big diameter (0.6–2 mm) hollow microspheres of PIEK, used for Inertial Confinement Fusion research, were prepared by using the microliquid technique and double‐layer latex technique. A new double T‐channel droplet generator was designed and developed for fabrication of controlled‐size PIEK hollow microspheres continuously. Study on manipulative condition of diameter and thickness of microspheres was done, and density matching impacting on the quality of shells was discussed. The structures of the PIEK hollow microspheres were characterized, and they possessed equal wall thickness and good spherical symmetry. The properties of the microspheres were detected, and the results showed that they showed good stability under cold environment and high temperature. Additionally, the PIEK hollow microspheres exhibited good mechanical and anti‐irradiation properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synergistic flame retardant effect of poly(ether sulfones) and polysiloxane on polycarbonate

Flame retardance of bisphenol A polycarbonate (PC) was improved by the co‐addition of poly (ether sulfones) (PES) and polysiloxane/acrylate copolymer (PSiA) while retaining a high rigidity and toughness. A UL 94 V‐0 rating for 1.6‐mm thick samples of PC/PES/PSiA blend with 10.0 wt % PES and 0.5 wt % PSiA (PC/10PES/0.5PSiA) was obtained. Its average heat release rate (av‐HRR) in a cone calorimeter measurement was decreased by 19% on the basis of PC/PES blend with 10.0 wt % PES. Scanning electron microscopy (SEM) morphologies of impact‐fractured surfaces revealed that the incorporation of 0.5 wt % PSiA decreased the dimensions of PES dispersed phase and provoked the uniform distribution of PES in PC matrix. Thermogravimetric‐Fourier transform infrared spectroscopy analysis results revealed that PSiA dominantly promoted the degradation of PC and the degraded products were combined with PES to form a superior flame‐retarded carbon layer. A higher sulfur and silicon content on the residue surface after vertical burning tests detected by SEM/energy dispersive spectrometer signified their accumulation during combustion. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Study on phenolphthalein poly(ether sulfone)‐modified cyanate ester resin and epoxy resin blends

In this work, the phenolphthalein poly(ether sulfone) (PES‐C)‐modified cyanate ester (CE) and epoxy (EP) blends were prepared. This work mainly discusses the curing behaviors, fracture toughness, dynamic mechanical properties, and thermal and mechanical properties of the blends. The Fourier transform infrared and differential scanning calorimetric analyses are used to confirm the curing behaviors, demonstrating that the main reaction pathways are not varied with the addition of PES‐C, but the reaction rate could be evidently accelerated. The fracture morphologies of the blends are observed by Scanning electron microscope (SEM) and the fracture causes of the failed surface are also analyzed. With the addition of PES‐C, the modified blends display higher fracture toughness (K_Ic) and impact strength when compared with neat CE. Domain sizes of the blends first increase then decrease with the addition of PES‐C. The results of dynamic mechanical analysis and thermogravimetric analysis show that the T_g, storage modulus, and thermal stability of the crosslink network slightly decreases with the addition of PES‐C. The mechanical strength of blends with the addition of PES‐C is far better than that of the blends without PES‐C both at ambient temperature and elevated temperature. POLYM. ENG. SCI., 55:2591–2602, 2015. © 2015 Society of Plastics Engineers     

Morphology controlled synthesis zinc oxide and reinforcement in polyhydroxyalkanoates composites

Micro‐sized ZnO crystals with different shapes have been successfully synthesized by a simple solvothermal reaction in glycol‐water binary solution or citrate solution. The morphology and size of the ZnO are strongly depended on synthetic environment. The growth of ZnO crystals with tunable shape was controlled by a suppressed crystal growth of the nonpolar plane and polar plane, due to the Tris selectively adsorbed on the different plane facets. Systematic reactions in the presence of different environments were conducted to control the formation of various well‐shaped ZnO crystals. In addition, the porous three‐dimensional microspheres possess larger surface area, which make it improving the mechanical properties of polymer compound. The mechanical properties of ZnO reinforced polyhydroxyalkanoates (PHA) composites have been tremendously improved. The elongation to break and ultimate tensile strength are increased by 41.2 and 56% compared with the pure PHA, respectively. The Young's modulus of the composites is also further improved. The results demonstrate the effectiveness of ZnO as reinforcement applications in polymer composites. POLYM. COMPOS., 35:1701–1706, 2014. © 2014 Society of Plastics Engineers     

Controlled release of berberine hydrochloride from alginate microspheres embedded within carboxymethyl chitosan hydrogels

Berberine hydrochloride is a natural medicine with wide clinical application. In this article, berberine hydrochloride was entrapped into alginate microspheres via an emulsification/gelation method. The size distribution of the microspheres was determined by a laser particle sizer. Drug distribution within the microspheres was determined by confocal laser scanning microscopy. Those drug‐loaded microspheres were further entrapped into carboxymethyl chitosan (CMC) hydrogel to form a new drug‐delivery system (DDS). The surface morphology of the DDS was observed using metallographic microscopy and scanning electron microscopy (SEM). The compression strength of the DDSs with alginate microspheres was found significantly higher than that of the pure hydrogel. The drug‐release performances of the DDS in phosphate buffer solution (PBS, pH 7.4), saline solution (pH 6.3), and hydrochloric acid solution (HAS, pH 1.2) were also studied. Decay of the DDS in PBS within 72–80 h results in a faster release; however, the steady release in saline solution could last for all the testing period without cleavage of the DDS. In HAS, because of the shrinkage of the DDS, release is fast in the first period and remains steady later. The DDS exhibits prospective in controlled steady release of drugs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Poly(vinyl alcohol)‐based polymeric membrane: Preparation and tensile properties

A series of poly(vinyl alcohol) (PVA)‐based single‐layer organic polymeric membranes were prepared via the crosslinking of PVA with different amounts of formaldehyde. Meanwhile, for comparison, both a three‐layer organic polymeric membrane and a hybrid composite membrane were also prepared by the layer‐upon‐layer method. Their thermal stability and tensile properties were investigated to examine the effect of crosslinking on the membrane performances. Thermogravimetric analysis and differential scanning calorimetry thermal analyses showed that the thermal degradation temperature of the single‐layer crosslinked membrane C reached up to 325°C. Tensile testing indicated that the three‐layer organic polymeric membrane E had excellent tensile strength among these single‐layer and three‐layer membranes. The swelling properties revealed that the swelling degree value of these membranes decreased with an increase in methanol concentration; this suggests that they were not easily swollen by the methanol solution, which is meaningful for the separation of organic mixtures. Field emission scanning electron microscopy images exhibited that the crosslinking of functional groups impacted their structures and confirmed that their mechanical properties were related to their structures. These findings suggest that the crosslinking of functional groups is an effective method for adjusting the tensile strength of PVA‐based organic polymeric membranes and related hybrid composite membranes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011