Preparation of polyhedral oligomeric silsesquioxane‐containing block copolymer with well‐controlled stereoregularity

Preparation of functional domains with a spacing of 10 nm is a benchmark set to fabricate next‐generation electronic devices. Organic–inorganic block copolymers form well‐ordered microphase separations with very small domain sizes. The design and preparation of a novel block copolymer consisting of syndiotactic polymethyl methacrylate (st‐PMMA) and polyhedral oligomeric silsesquioxane (POSS)‐functionalized polymethacrylate, designated as st‐PMMA‐b‐PMAPOSS, which can recognize functional molecules, are reported. The st‐PMMA segments form a helical structure and encapsulate C₆₀ in the helical nanocavity, leading to the formation of an inclusion complex. Although the ordering of the domains is not high, C₆₀ domains that are in a quasi‐equilibrium state, with about 10‐nm domain spacings, are generated using st‐PMMA‐b‐PMAPOSS that can recognize functional molecules. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2181–2189     

Block copolystyrene derivatives having flexible alkylsulfonated side chains and hydrophobic alkoxy chains as a proton exchange membrane for fuel cell application

A series of block copolystyrene derivatives, poly{[4‐(4‐sulfobutyloxy)styrene]_x‐block‐[4‐(n‐butoxystyrene)]_y} (PSBOS_x‐b‐PnBOS_y), containing a flexible alkylsufonated side chain and hydrophobic alkoxy chain with various ion exchange capacities (IECs) have been synthesized based on living anionic polymerization. The resulting crosslinked membranes were prepared using 4,4′‐methylene‐bis[2,6‐bis(hydroxyethyl)phenol] as the crosslinker in the presence of methanesulfonic acid. The crosslinked PSBOS_2.2‐b‐PnBOS₁ membrane with IEC of 2.89 mequiv g^?1 displays a high proton conductivity (0.01 S cm^?1) at 30% relative humidity and 80 °C, which is comparable to that of Nafion. The well‐developed phase separation and the continuous hydrophilic domains in the crosslinked PSBOS_2.2‐b‐PnBOS₁ membranes have been observed in a transmission electron microscope image. Moreover, the dynamic mechanical analysis measurement and Fenton's reagent testing show that the crosslinked PSBOS_x‐b‐PnBOS_y membranes have good mechanical properties and oxidative stability. These results indicate that the introduction of flexible alkylsulfonated side chains to the polystyrene main chains positively affect both the proton conductivity and oxidative stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Intelligent crew-cut aggregates formed by thermosensitive block copolymers and their multiple morphologies

The thermosensitive block copolymer poly(2-cinnamoylethyl methacrylate)-block-poly(N-isopropylacrylamide) (PCEMA-b-PNIPAAm) can form crew-cut aggregates with multiple morphologies under various micellization conditions. Spherical, rod-like, vesicular, lamellar aggregates, and large compound micelles were obtained from the block copolymers. The effects of different conditions, such as the copolymer composition, the nature of the common solvent, the initial copolymer concentrations, and the water content on the morphologies of the aggregates were studied in detail. The thermosensitive property of the aggregates was investigated through measuring the change of the dimension of the aggregates with changing the external temperature.     

Synthesis of poly(arylene ether sulfone)‐block‐sulfonated polybutadiene: the selective post‐sulfonation of block copolymers as proton exchange membranes

A series of poly(arylene ether sulfone)‐block‐sulfonated polybutadiene (PAES‐b‐sPB) with different ion exchange capacities (IECs) were synthesized and evaluated as proton exchange membranes (PEMs) for possible applications in fuel cells. These sulfonated block copolymers were synthesized via condensation reaction between modified PAES and PB prepolymers, followed by selective post‐sulfonation of PB blocks using acetyl sulfate as the sulfonating reagent. The sulfonic groups were only attached onto PB blocks due to the high reactivity of double bonds to acetyl sulfate. The success of synthesis and selective post‐sulfonation were all confirmed by the Fourier transform infrared (FT‐IR) and nuclear magnetic resonance (NMR) spectra. PAES‐b‐sPB had good film‐forming ability and thermal stability. Mechanical properties of membranes varied with the sulfonation. The presence of sulfonic groups increased the tensile strength and Young's modulus but decreased the elongation at break. Transmission electron microscopy (TEM) images showed large ionic aggregates in membranes. Phase separation as well as the interconnected sulfonate groups which only localized on flexible PB blocks led to these ionic domains. The proton conductivity increased with the increasing IEC and temperature. With relatively low IEC, most membranes still exhibited sufficient proton conductivity. The above results indicated this strategy could be a prospective choice to prepare novel PEMs. Copyright © 2010 John Wiley & Sons, Ltd.     

Preparation and characterization of layer‐by‐layer self‐assembly membrane based on sulfonated polyetheretherketone and polyurethane for high‐temperature proton exchange membrane

A concept of preparing high‐temperature proton exchange membranes with layer‐by‐layer (LBL) self‐assembly technique was proposed and the sulfonated polyetheretherketone (SPEEK) and polyurethane (PU) with 200 LBL deposition cycles denoting (SPEEK/PU)₂₀₀ membrane was prepared in this research. Owing to the strong electrostatic interaction between ? group in SPEEK and ? C? N⁺ group in PU, (SPEEK/PU)₂₀₀ membrane with LBL self‐assembly structure showed a favorable structural stability. The phosphoric acid (PA)‐doped (SPEEK/PU)₂₀₀ membrane showed a higher proton conductivity relative to PA doped SPEEK/PU membrane by solution casting method (SPEEK/PU)₂₀₀/40%PA membrane possessed a proton conductivity value of 2.90 × 10^?2 S/cm at 150 °C under anhydrous conditions. The LBL self‐assembly structure provided a possibility to reduce the negative effect from polymer skeleton blocking charge carrier species even immobilizing protons. Moreover, the (SPEEK/PU)₂₀₀ membrane presented the particularly noteworthy mechanical property even with PA doping. The tensile stress values at break were 72.8 and 24.1 MPa, respectively, for (SPEEK/PU)₂₀₀ and (SPEEK/PU)₂₀₀/40%PA membrane at room temperature, which were obviously higher than the reported values of 15.9 and 2.81 MPa for SPEEK/PU and SPEEK/PU/60%PA membrane. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 3446–3454     

Facile syntheses,morphologies, and optical absorptions of P3HT coil‐rod‐coil triblock copolymers

Here we report syntheses, photophysical properties, and morphologies of a series of coil‐rod‐coil ABA triblock copolymers containing highly regioregular poly(3‐hexylthiophene) (P3HT) as the central rod block. A new methodology, based on the coupling reaction between living polymeric anions [polystyrene, polyisoprene, and poly(methyl methacrylate)] and aldehyde terminated P3HT, was successfully developed to synthesize the triblock copolymers with low polydispersities. This coupling reaction was effective for building blocks with a variety of molecular weights; therefore, a good variation in compositions of the triblock copolymers could be feasibly achieved. The non‐P3HT coil segments and the solvents were found to exhibit noticeable effects on morphologies of the spin‐coated thin films. Attachment of the coil segments to P3HT did not change the optical absorption of the P3HT segment as the block copolymers were dissolved in solution regardless the chemical structure and the molecular weight of the coil segment. Interestingly, different UV–vis absorption behaviors were observed for the spin‐coated thin films of the block copolymers, which closely related to their morphologies. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3311–3322, 2010     

An insight into the schizophrenic self‐assembly of thermo and proton sensitive graphene oxide grafted block copolymer

In order to study the self‐assembly of block copolymer grafted from graphene oxide (GO) by the fluorescence of GO, poly(ε‐caprolactone) (PCL)‐block‐poly(dimethyl aminoethyl methacrylate) (PDMAEMA) is grafted from its surface using consecutive ring opening (ROP) and atom transfer radical polymerization (ATRP). GO‐g‐(PCL₁₃‐b‐PDMAEMA₁₁₇) (GPCLD) at pH 9.2 exhibits cloud point (T_c) at 32 °C. At pH 9.2 HRTEM images indicate schizophrenic morphology from vesicle at 26 °C to annular ring at 30 °C followed by giant size aggregation at 38 °C. But the reference block copolymer (PCL₁₄‐b‐PDMAEMA₁₂₆, PCLD), synthesized using benzyl alcohol as ROP initiator, exhibits only core–shell morphology whose size increases with rising temperature at pH 9.2. GPCLD solution exhibits good photoluminescence (PL) property arising from GO at pH 9.2 and PL‐intensity increases abruptly during phase transition. Both T_c and size of GPCLD assembly can be reversibly tuned by CO₂ and N₂ gas purging. ¹H NMR spectra exhibit a gradual shift of resonance peaks of the protons on CO₂ bubbling. Thus at pH 9.2 and at 38 °C the GPCLD acts as a good CO₂ sensor. Additionally, the GPCLD vesicle can load hydrophobic guest molecules which can be released by triggering with CO₂. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3878–3887     

Controlled co‐solvent vapor annealing and the importance of quenching conditions in thin‐film block copolymer self‐assembly

A controlled co‐solvent vapor annealing system was designed and constructed to investigate the effects of solvent vapor activity during the rapid ambient quenching process on the morphology of a cylinder‐forming poly(styrene)‐b‐poly (ethylene oxide) (PS‐PEO) annealed in toluene and water vapor. A phase transformation from cylinders in the bulk to close‐packed spheres in swollen thin films occurred, which was reversed upon quenching with dry nitrogen. Quenching with humidified nitrogen preserved the spherical morphology but could significantly alter domain spacing and reduce long‐range order in the dried films under some circumstances. Specifically, long‐range order in the quenched films was found to decrease as the quenching humidity decreased from the humidity used during annealing, and the best long‐range order was obtained when the humidity remained consistent throughout both annealing and quenching. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1125–1130     

Synthesis and characterization of fluorine‐containing PAA‐b‐PTPFCBPMA amphiphilic block copolymer

A series of perfluorocyclobutyl (PFCB) aryl ether‐based amphiphilic diblock copolymers containing hydrophilic poly(acrylic acid) (PAA) and fluorophilic poly(p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate) segments were synthesized via successive atom transfer radical polymerization (ATRP). 2‐MBP‐initiated and CuBr/N,N,N′,N′,N″‐pentamethyldiethylenetriamine‐catalyzed ATRP homopolymerization of the PFCB‐containing methacrylate monomer, p‐(2‐(p‐tolyloxy)perfluorocyclobutoxy)phenyl methacrylate, can be performed in a controlled mode as confirmed by the fact that the number‐average molecular weights (M_n) increased linearly with the conversions of the monomer while the polydispersity indices kept below 1.38. The block copolymers with narrow molecular weight distributions (M_w/M_n ≤ 1.36) were synthesized by ATRP using Br‐end‐functionalized poly(tert‐butyl acrylate) (PtBA) as macroinitiator followed by the acidolysis of hydrophobic PtBA block into hydrophilic PAA segment. The critical micelle concentrations of the amphiphilic diblock copolymers in different surroundings were determined by fluorescence spectroscopy using N‐phenyl‐1‐naphthylamine as probe. The morphology and size of the micelles were investigated by transmission electron microscopy and dynamic laser light scattering, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Water‐soluble top coats for orientation control of liquid crystal‐containing block copolymer films

An easily removable, water‐soluble top coat of polyvinylpyrrolidone (PVP) is used to control the orientation of microdomains in a liquid crystalline block copolymer (LC BCP, poly(ethylene oxide)‐block‐poly(6‐(4‐methoxy‐azobenzene‐4′‐butyl) hexyl methacrylate)). The corresponding LC homopolymer is also investigated for comparison. Atomic force microscopy is used to determine the orientation of the cylindrical microdomains of the LC BCP. UV–vis spectroscopy and grazing incidence wide‐angle X‐ray scattering are used to determine the orientation of the LC mesogens in the LC homopolymer and the LC BCP films annealed both with and without a top coat. Once the LC BCP morphology is self‐assembled, the PVP top coat layer can be easily removed with water or alcohol. The facile removal of the top coat improves the processability of BCPs in technological applications, and enables direct investigation of the BCP morphology in scientific studies. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1569–1574     

Amphiphilic diblock copolymers bearing pendant aromatic acetal groups: Synthesis and tunable pH‐triggered assembly/disassembly transition behavior

A novel aromatic acetal‐based acid‐labile monomer 2‐phenyl‐5‐ethyl‐5‐acryloxymethyl‐1,3‐dioxacyclohexane (HEDPA) was synthesized and polymerized by reversible addition fragmentation chain transfer (RAFT) polymerization using alkynyl functional chain transfer agent (CTA‐Alk). Afterward, a series of amphiphilic diblock copolymers composed of fixed hydrophobic poly(2‐phenyl‐5‐ethyl‐5‐acryloxymethyl‐1,3‐dioxacyclohexane) (PDAEP) segments and various lengths of hydrophilic mPEG segments were prepared through click reaction between alkynyl‐terminated PDAEP and azido‐terminated mPEG. The self‐assembly behaviors of the diblock copolymers were investigated by dynamic light scattering (DLS), transmission electron microscopy (TEM), fluorescence spectroscopy, and ¹H NMR. These results indicated that the diblock copolymers could self‐assemble into nano‐sized micelles with PDAEP cores and PEG coronas in aqueous solution. DLS, fluorescence spectroscopy and UV–vis spectroscopy were used to monitor the pH‐triggered assembly/disassembly transition of the micelles. These results showed that the assembly/disassembly transition behaviors of the diblock copolymers micelles can be adjusted by changing the lengths of the mPEG segments. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1537–1547     

Synthesis and self‐assembly of thermotropic block copolymer with long alkyl tethered cage silsesquioxane in the side chain

Thermotropic POSS‐containing poly(methacrylate) with long alkyl chain tethered polyhedral oligomeric silsesquioxane (POSS) in the side chain and the block copolymers (PMMA‐b‐PMAC11POSS) were developed by through living anionic polymerization. The resulting polymers indicated a phase transition temperature at 112 °C from spherocrystal to isotropic phase. The POSS‐containing polymer segments tended to form matrix of microphase‐separated nanostructures in the bulk even in the very low volume fraction, for instance, PMMA cylindrical nanostructure was obtained by PMMA₁₇₅‐b‐PMAC11POSS₁₁ (?_PMAC11POSS = 0.44). The control of thin film morphology was carried out by not only solvent annealing, but also thermal annealing, resulting in the formation of well‐ordered dot‐ and fingerprint‐type nanostructures. This is the first report in a series of POSS‐containing block polymers that are capable for thermal annealing to generate well‐ordered microphase‐separated nanostructures in thin films. The novel thermotropic POSS‐containing block copolymer offers a promising material for block copolymer lithography. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Multiple morphologies of the aggregates from self‐assembly of diblock copolymer with relatively long corona‐forming block in dilute aqueous solution

Reported here is self‐assembly behavior in selective solvent of diblock copolymers with relatively long corona‐forming block compared to core‐forming block. Three diblock copolymers, poly(ethylene glycol) monomethyl ether‐b‐poly(methacryloyl‐L ‐leucine methyl ester), also denoted as MPEG‐b‐PMALM copolymer, were prepared by fixing MPEG block with an average number of repeating units of 115, whereas varying PMALM block with an average number of repeating unit of 44, 23, 9, respectively. Multiple morphologies, such as sphere, cylinder, vesicle, and their coexisted structures from self‐assembly of these diblock copolymers in aqueous media by changing block nonselective solvent and initial polymer concentration used in preparation, were demonstrated directly via TEM observation. These results herein might, therefore, demonstrate as an example that a wide range of morphologies can be accessed not only from “crew‐cut micelles” but also from “star‐micelles” by controlling over preparation strategies. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 364–371, 2010     

Synthesis and characterization of a film‐forming,crosslinked, amphiphilic block copolymer of butadiene and acrylamide

An amphiphilic block copolymer of acrylamide and butadiene was synthesized by the polymerization of acrylamide in the presence of the crosslinker N,N′‐methylene bisacrylamide initiated by a hydroxyl‐terminated polybutadiene/V(V) macroredox initiator. The product had good film‐forming ability. It was characterized by IR and NMR spectroscopy, viscosity, swelling, and microhardness measurements, scanning electron micrography, and differential scanning calorimetry. A good film was obtained from the block copolymer with a greater proportion of butadiene; it had greater permeability for nonpolar solvents, and it was poorly permeable to water and other polar solvents. The film swelled in polar and nonpolar solvents and had almost the same capacity for the loading and release of hydrophilic and hydrophobic dyes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3290–3303, 2006     

Synthesis and characterization of novel phosphonated and sulfonated poly(styrene–isobutylene–styrene) for fuel cell and protective clothing applications

A novel aromatic block–graft copolymer of sulfonated poly(styrene–isobutylene–styrene)‐graft‐poly(vinyl phosphonic acid) (SIBS‐g‐PVPA SO₃H) was synthetized for direct methanol fuel cell (DMFC) and chemical and biological protective clothing (CBPC) applications. The polystyrene (PS) blocks of SIBS were chloromethylated via a Friedel–Crafts reaction to obtain the macroinitiator SIBS‐CH₂Cl. Atom transfer radical polymerization (ATRP) was performed to graft VPA to the chloromethylated groups of the macroinitiator and yield SIBS‐g‐PVPA, which was subsequently sulfonated using acetyl sulfate as the sulfonating agent. After each functionalization step, a membrane was prepared by using the solvent casting technique. The final membrane was composed of triblock SIBS as the backbone, PVPA grafts attached to the chloromethylated PS end blocks and sulfonic groups in the non‐chloromethylated PS units. A comprehensive materials characterization study (e.g., GPC, FTIR, TGA, EA) was performed to confirm proper functionalization of each material. Unique ionic interactions (i.e., crosslinking via formation of sulfonate–phosphonium complexes) arose between the phosphonic and sulfonic groups (i.e., PO₃H₂ and SO₃H, respectively) that enhanced the water absorption capabilities, thermal and oxidative stability, and the transport properties of SIBS. The SIBS‐g‐PVPA SO₃H membrane presented high Nafion ® normalized selectivity and separation efficiency, indicating that this ionomer adequately functions for both applications. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 1424–1435     

Morphology control and inducing a curvature on the domain interface by increasing the steric bulk of polymethacrylate in POSS‐containing diblock copolymers

Herein, a novel rod‐coil type polyhedral oligomeric silsesquioxane (POSS)‐containing diblock copolymer was designed to enable the self‐assembly of hexagonally packed cylinders of the POSS‐containing domain in a poly(n‐butyl methacrylate) (PnBMA) matrix. When POSS‐containing diblock copolymers were synthesized with polyisoprene or poly(methyl methacrylate), cylindrical structures could not be obtained as POSS‐containing polymers form stretched rigid rods. This makes the formation of cylindrical structures with the POSS‐containing domain entropically unfavorable. Therefore, to obtain the cylindrical structures, we constructed a novel diblock copolymer using PnBMA to increase the steric bulk and segment volume of the flexible coil. Steric crowding of the butyl groups reduces the entropic free stretching energy of the PnBMA chains, which in turn encourages the formation of a POSS‐containing hexagonally packed cylindrical structure within the PnBMA matrix as the system minimizes the total free energy of the thermodynamically stable nanostructure. Small angle X‐ray scattering and transmission electron microscopy analyses indicated that cylinders of the POSS domain had formed. Oxygen plasma etching was then used on the thin film to selectively remove the PnBMA domain to yield line and space structures with a high degree of long‐range order and a 14 nm feature size. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2234–2242     

The research on multi‐responsive azobenzene block copolymer and its self‐assembly behavior

The azobenzene‐based amphiphilic copolymers have drawn significant attention as a kind of multi‐responsive smart materials. The demand on deeper investigation of how the azobenzene group influences the micelles formation and light‐responsive behavior on molecular level is very urgent. In this article, multi‐responsive block copolymers, poly (acrylic acid)‐block‐poly[4'‐[[(2‐Methacryloyloxy)ethyl]ethylainino]azobenzene‐co‐poly (ethylene glycol) methyl ether methacrylate] (PAA‐b‐P (AzoMA‐co‐PEGMA)), with pH‐, light‐ and reduction‐responsiveness were synthesized by the monomers of AzoMA, PEGMA and acrylic acid via reversible addition‐fragmentation chain transfer polymerization (RAFT). The amphiphilic block copolymer presented aggregation‐induced emission effect, and it was pH, light, and reduction responsive. The results showed that the micelle size decreased with the decreasing of pH within a certain range. However, the particle size of micelles increased significantly when the pH was 4. Once adding reduction agent, the micelles were disassembly. Fluorescent molecule of Nile red was selected as a hydrophobic guest molecule to study the properties of encapsulating and releasing abilities of block copolymer micelles for guest molecules. The results showed that the loading capacity of three kinds of copolymer micelles was closely related to the aggregates formed by the hydrophobic block, mainly azobenzene block. Besides, the block copolymer micelles could release a certain amount of Nile red under the irradiation of UV light, the reduction with Na₂S₂O₄ as reductant, and the exposure to alkaline environment. The mechanism of how the different status of azobenzene group influenced the self‐assembly and multi‐responsive behavior was explored on molecular level.     

Hyperbranched block copolymer from AB2 macromonomer: Synthesis and its reaction‐induced microphase separation in epoxy thermosets

In this contribution, we reported the synthesis of a hyperbranched block copolymer composed of poly(ε‐caprolactone) (PCL) and polystyrene (PS) subchains. Toward this end, we first synthesized an α‐alkynyl‐ and ω,ω′‐diazido‐terminated PCL‐b‐(PS)₂ macromonomer via the combination of ring‐opening polymerization and atom transfer radical polymerization. By the use of this AB₂ macromonomer, the hyperbranched block copolymer (h‐[PCL‐b‐(PS)₂]) was synthesized via a copper‐catalyzed Huisgen 1,3‐dipolar cycloaddition (i.e., click reaction) polymerization. The hyperbranched block copolymer was characterized by means of ¹H nuclear magnetic resonance spectroscopy and gel permeation chromatography. Both differential scanning calorimetry and atomic force microscopy showed that the hyperbranched block copolymer was microphase‐separated in bulk. While this hyperbranched block copolymer was incorporated into epoxy, the nanostructured thermosets were successfully obtained; the formation of the nanophases in epoxy followed reaction‐induced microphase separation mechanism as evidenced by atomic force microscopy, small angle X‐ray scattering, and dynamic mechanical thermal analysis. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 368–380     

Synthesis and characterization of poly(arylene ether ketone)s bearing pendant sulfonic acid groups for proton exchange membrane materials

A bisphenol monomer (2,5‐dimethoxy)phenylhydroquinone was prepared and further polymerized to obtain poly(arylene ether ketone) copolymers containing methoxy groups. After demethylation and sulfobutylation, a series of novel poly(arylene ether ketone)s bearing pendant sulfonic acid group (SPAEKs) with different sulfonation content were obtained. The chemical structures of all the copolymers were analyzed by ¹H NMR and ¹³C NMR spectra. Flexible and tough membranes with reasonably good mechanical properties were prepared. The resulting side‐chain‐type SPAEK membranes showed good dimensional stability, and their water uptake and swelling ratio were lower than those of conventional main‐chain‐type SPAEK membranes with similar ion exchange capacity. Proton conductivities of these side‐chain‐type sulfonated copolymers were higher than 0.01 S/cm and increased gradually with increasing temperature. Their methanol permeability values were in the range of 1.97 × 10^?7–5.81 × 10^?7 cm²/s, which were much lower than that of Nafion 117. A combination of suitable proton conductivities, low water uptake, low swelling ratio, and high methanol resistance for these side‐chain‐type SPAEK films indicated that they may be good candidate material for proton exchange membrane in fuel cell applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010