A sulfonated poly（ether ether ketone） （SPEEK） membrane with a fairly high degree of sulfonation （DS） can swell excessively and even dissolve at high temperature. To solve these problems, insolvable functionalize...A sulfonated poly（ether ether ketone） （SPEEK） membrane with a fairly high degree of sulfonation （DS） can swell excessively and even dissolve at high temperature. To solve these problems, insolvable functionalized silica powder with sulfonic acid groups （SiOx-S） was added into the SPEEK matrix （DS = 55.1%） to prepare SPEEK/ SiOx-S composite membranes. The decrease in both the swelling degree and the methanol permeability of the membranes was a dose-dependent result of addition of the SiOx-S powder. Pure SPEEK membrane swelled 52.6% at 80℃, whereas the SPEEK/SiOx-S （15%, by mass） membrane swelled only 27.3% at the same temperature. From room temperature to 80℃, all SPEEK/SPEEK/SiOx-S composite membranes had methanol permeability of about one order of magnitude lower than that ofNafion115. Compared with pure SPEEK membranes, the addition of the SiOx-S powder not only leads to higher proton conductivity, but also increases the dimensional stability at higher temperatures, and greater proton conductivity can be achieved at higher temperature. The SPEEK/SiO4-S （20%, by mass） membrane could withstand temperature up to 145℃, at which in 100% relative humidity （RH） its proton conductivity exceeded slightly that of Nafion 1 15 membrane and reached 0.17 S·cm^-1, while pure SPEEK membrane dissolved at 90℃. The SPEEK/SiOx-S composite membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.展开更多
A sulfonated poly（ether ether ketone） （SPEEK） membrane with fairly high degree of sulfonation （DS） swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein p...A sulfonated poly（ether ether ketone） （SPEEK） membrane with fairly high degree of sulfonation （DS） swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein poly（ether sulfone） （SPES-C, DS= 53.7%） is blended with the SPEEK matrix （DS= 55.1%, 61.7%） to prepare SPEEKJSPES-C blend membrane. The decrease in swelling degree and methanol permeability of the membrane is dose-dependent. Pure SPEEK （DS = 61.7%） membrane dissolves completely in water at 70℃, whereas the swelling degree of the SPEEK （DS = 61.7%）/SPES-C （40%, by mass） membrane is 29.7% at 80℃. From room temperature to 80℃, the methanol permeability of all SPEEK （DS = 55.1%）/SPES-C blend membranes is about one order of magnitude lower than that of Nafion 115. At higher temperature, the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved. The SPEEK （DS = 55.1%）/SPES-C （40%, by mass） membrane can withstand temperatures up to 150℃. The proton conductivity of SPEEK （DS = 55.1%）/SPES-C （30%, by mass） membrane approaches 0.16 S·cm^-1, matching that of Nafion 115 at 140℃ and 100% RH, while pure SPEEK （DS = 55.1%） membrane dissolves at 90℃. The SPEEK/SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.展开更多
Sulfonated poly（ether ketone）s containing 3,5-dimethyl phthalazinone moieties （SPPEK-DMs） with different degrees of sulfonation （DS） were synthesized via direct polycondensation from 4-（3,5-dimethyl-4-hydroxyph...Sulfonated poly（ether ketone）s containing 3,5-dimethyl phthalazinone moieties （SPPEK-DMs） with different degrees of sulfonation （DS） were synthesized via direct polycondensation from 4-（3,5-dimethyl-4-hydroxyphenyl）-2,3- phthalazinone, 4,4＇-difluorobenzophenone and 3,3＇-disulfonate-4,4＇-difluorobenzophenone. The chemical structure of SPPEK-DMs was characterized by FTIR and 1H-NMR. Thermal stability of SPPEK-DMs was characterized by the thermogravimetric analysis. The membranes prepared from SPPEK-DMs exhibited ion exchange capacities （IEC） ranging from 0.93 mmol.g-1 to 1.86 mmol.g-1. Water uptake, swelling, oxidative stability and methanol permeability of SPPEK- DMs membranes were investigated. SPPEK-DMs membranes exhibited high oxidative stability. The methanol permeability values of SPPEK-DMs membranes were in the range 5.15× 10^-8-6.61×10^-7 cm^2.s-1, which was much lower than those of Nafion117. The proton conductivity of SPPEK-DM40 membranes was 1.1 ×10^-2 S.cm^-1 at 70℃.展开更多
A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place ...A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place at the para position of the pendant phenyl rings because of the specially designed parent polymer. The position and degree of sulfonation were characterized by ^1H-NMR and elemental analysis. The sulfonated polymers are highly soluble in common organic solvents, such as dimethylsulfoxide, N,N＇-dimethylacetamide, dimethylformamide, ethylene glycol monomethyl ether, and can be readily cast into tough and smooth films from solutions. The films showed good thermal and hydrolysis stabilities. Moreover, Fenton＇s reagent test revealed that the films exhibited superior stability to oxidation. The proton conductivities of the films were comparable with Nation 117 under same conditions. The membrane electrode assembly （MEA） prepared with the asmade film （706 EW, 100 μm dry thickness） shows better cell performance than Nation 115-MEA in the whole current density range.展开更多
Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks...Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.展开更多
N,N＇-Bis（3-hydroxyphenyl）-1,8,4,5-naphthalenetetracarboxylic bisimide was prepared from the reaction of 1,8,4,5-naphthalenetetrcarboxylic acid dianhydride and 2-aminophenol in N, N-dimethylformamide. Polymerization...N,N＇-Bis（3-hydroxyphenyl）-1,8,4,5-naphthalenetetracarboxylic bisimide was prepared from the reaction of 1,8,4,5-naphthalenetetrcarboxylic acid dianhydride and 2-aminophenol in N, N-dimethylformamide. Polymerization of this bisimide with 4,4＇-difluorodiphenylsulfone and disodium 3,3＇-disulfonate4,4＇-difluorodiphenylsulfone gave ion-exchange sulfonated poly（ether sulfone）. The structure of the title compound was characterized with H-NMR and its polymer was characterized with FT-IR.展开更多
A series of multiblock sulfonated poly(arylene ether sulfone)s(SPAES)with various block lengths and predictable ion exchange capacity were synthesized from 4,4’-difluorodiphenyl sulfone,4,4’-dihydrodiphenyl sulfone ...A series of multiblock sulfonated poly(arylene ether sulfone)s(SPAES)with various block lengths and predictable ion exchange capacity were synthesized from 4,4’-difluorodiphenyl sulfone,4,4’-dihydrodiphenyl sulfone and 4,4’-biphenol by one-pot and two-pot polymerization.;H-NMR and FTIR spectra confirmed the structure that sulfonic acid groups were introduced precisely on the poly(arylene ether sulfone)s by post-sulfonation which resulted in controllable sulfonation degree.The proton exchange membranes(PEMs)-based SPAES displayed excellent dimensional,thermal,antioxidant stability,proton conductivity and mechanical properties(maximum tensile stress>35 MPa).Thermogravimetric analysis indicated the prepared SPAES began to degrade above 310℃.The effects of polymerization processes,those were,one-pot hydrophobic segment process,one-pot hydrophilic segment process and two-pot process,on the properties of polymers were investigated.The proton conductivity and microphase separation of SPAES PEMs increased in order of those prepared by one-pot hydrophobic segment process,two-pot process and one-pot hydrophilic segment process.The highest conductivities of SPAES synthesized by the above processes under 80℃ and 100%relative humidity were 213(MS4),297(MB3)and 360 mS·cm^(-1)(MQ2),respectively.展开更多
A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through ...A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.展开更多
Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation ...Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation provides incremental proton conductivity to the membranes, whereas mechanical degradation drastically reduces device stability. On this basis, we describe here the effects of two different ex situ aging processes on sulfonated poly(ether ether ketone) membranes: hydrationdehydration cycling and prolonged hydrothermal treatment. Both aged membranes exhibited enhanced phase separation under the hydrated conditions, as characterized by small angle X-ray scattering.However, when the aged membranes were dried again, the nanostructure of the membranes aged via the hydration-dehydration cycling was recoverable, whereas that of the membranes aged via prolonged hydrothermal treatment was irreversible. Furthermore, the two differently aged membranes showed clear differences in thermal, mechanical, and electrochemical properties. Finally, we implemented both aged membranes in fuel cell application. The sample aged via hydration-dehydration cycling maintained its improved cell performance, whereas the sample aged via hydrothermal treatment showed drastically reduced cell performance after durability test for 50 h.展开更多
Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chlorometh...Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.展开更多
A novel series of poly（aryl ether sulfone ketone）s （PPESKs） containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were...A novel series of poly（aryl ether sulfone ketone）s （PPESKs） containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were between 38,330 and 67,900. The glass transition temperatures （Tg） and 5% decomposition temperatures were ranged in 253-269 ℃ and 488-500 ℃, respectively, The structures of these copolymers were confirmed by FT-IR and ^1H NMR. Moreover, all the resultant copolymers were amorphous determined by wide angle X-ray diffraction （WAXD）.展开更多
1, 2-Diliydro-4-(4-hydroxyphenyl)(2H)phthalazin-1-one(DHPZ) was sulfonated in concentrated Sulfuric acid. Poly(phthalazinone ether ketone) containing pendant sodium sulfonate group was synthesized from sulfonated and ...1, 2-Diliydro-4-(4-hydroxyphenyl)(2H)phthalazin-1-one(DHPZ) was sulfonated in concentrated Sulfuric acid. Poly(phthalazinone ether ketone) containing pendant sodium sulfonate group was synthesized from sulfonated and pure 1,2-dihydro-4-(4-hydroxyphenyl)(2H)phthalazin-1-one, and 4,4'-difluorodiphenylketone. The sulfonated monomer and sulfonated polymer were characterized with FT-IR and H-1-NMR.展开更多
Novel poly（aryl ether sulfone ketone）s （PAESK） were synthesized from bisphenol A （BPA）, 9,9＇-bis（4-hydroxyphenyl） fluorene （BHPF）, 4,4＇-dichlorodiphenylsulfone （DCS） and 4,4＇-difluorobenzophenone （DFB...Novel poly（aryl ether sulfone ketone）s （PAESK） were synthesized from bisphenol A （BPA）, 9,9＇-bis（4-hydroxyphenyl） fluorene （BHPF）, 4,4＇-dichlorodiphenylsulfone （DCS） and 4,4＇-difluorobenzophenone （DFB） via nucleophilic substitution polymerization, which were subsequently used to fabricate ultrafiltration membrane by phase-inversion method for high temperature condensed water treatment. The obtained high molecular weight co-polymers with fluorene group with good solubility and good thermal stability, can be easily cast into flexible, white and non-transparent fiat films. The influence of molar ratio of BPA and BHPF on the properties of the prepared co-polymers and membranes was investigated in detail. SEM study of the morphology of the membranes indicated that the prepared membranes possessed homogeneous pores on the top surface and were sponge-like or finger-like in cross-section. Pure water flux of the membranes increased from 71.87 L·m-2.h-1 to 247.65 L·m-2.h-1, while the retention of BSA decreased slightly, and the water contact angle decreased from 82.1 ° to 55.6° with the PVP concentration from 0 wt% to 10 wt%. With increasing concentration of PVP, the mechanical properties of membranes decreased, while the thermal stability increased. The permeate flux measurement showed that the PAESK membrane had the potential for high temperature condensed water treatment.展开更多
A novel type of crosslinkable poly（aryl ether sulfone）（PAES） bearing an allyl pendant（PES-OAllyl） was synthesized by a grafting reaction of hydrophenyl-containing PAES（PES-OH） and allyl bromide. PES-OH was pre...A novel type of crosslinkable poly（aryl ether sulfone）（PAES） bearing an allyl pendant（PES-OAllyl） was synthesized by a grafting reaction of hydrophenyl-containing PAES（PES-OH） and allyl bromide. PES-OH was prepared by a demethylation reaction of a methoxyphenylated PAES（PES-OCH3） in the presence of pyridine/hydrochlo- ride. The PES-OCH3 was synthesized by an aromatic nucleophilic substitution of bis（4-chlorophenyl）sulfone and （p-methoxy）phenylhydroquinone. Both DSC and solubility investigation were used to study the crosslinking behavior of PES-OAllyl. After heat treatment, the glass transition temperature（Tg） value of PES-OAllyl sharply increased from 165 ℃ to 227 ℃. Meanwhile, PES-OAllyl changed from a soluble polymer to an insoluble thermoset. In addition, TGA（thermogravimetric analysis） result suggests that the thermal stability of the crosslinked product was improved. All the data prove that the crosslinked PES-OAllyl could be a potential solvent-resistance high-performance material.展开更多
A series of cardo poly（aryl ether sulfone） copolymers bearing pendent sulfonic acid groups （SPES-X） have been prepared by a facile chemical graft method. The structure was confirmed by 1H-NMR spectra. The side-cha...A series of cardo poly（aryl ether sulfone） copolymers bearing pendent sulfonic acid groups （SPES-X） have been prepared by a facile chemical graft method. The structure was confirmed by 1H-NMR spectra. The side-chain-type SPES-X membranes show significantly reduced swelling behavior and excellent mechanical properties as well as appropriate proton conductivity compared to the main-chain-type sulfonated polymers with similar ion exchange capacity （IEC） value. Moreover, they show methanol permeability in the range of 0.6 × 10^-7-5.7 × 10^-7 cmE/s which is lower than that of Nafion 117. All the results indicate that the SPES-Xmembranes are promising candidates for the direct methanol fuel cells.展开更多
A novel poly(ether sulfone ketone)containing the phthalazinone moiety was prepared by the reaction of4-)4-hydroxyphenyl)(2H)phthalazin-1-one with activated dichloro-monomers.The polymer was characterized by FT-IR,H-1-...A novel poly(ether sulfone ketone)containing the phthalazinone moiety was prepared by the reaction of4-)4-hydroxyphenyl)(2H)phthalazin-1-one with activated dichloro-monomers.The polymer was characterized by FT-IR,H-1-NMR,DSC,TGA and X-ray diffraction.展开更多
A series of Poly（arly ether sulfone ether ketone）s containing pendant methyl groups were synthesized by the reaction of 4,4＇-[sulfonylbis （1,4-phenylene）dioxy] dibenzoyl chloride （SODBC） with 4,4＇- diphenoxy d...A series of Poly（arly ether sulfone ether ketone）s containing pendant methyl groups were synthesized by the reaction of 4,4＇-[sulfonylbis （1,4-phenylene）dioxy] dibenzoyl chloride （SODBC） with 4,4＇- diphenoxy diphenylsulfone （DPODPS）, 4,4＇- di（2-methylphenoxy） diphenylsulfone （o-Me-DPODPS）, 4,4＇- di（3-methylphenoxy） diphenylsulfone （m-Me-DPODPS）, 4,4＇- di （2,6-bimethylphenoxy） biphenylsulfone（o-Me2-DPODPS） respectively, in a mixture of 1,2-dichloroethane （DCE） and N-methylpyrrolidone （NMP）. These reactions were catalyzed by anhydrous aluminum chloride （AlCl）. The characteristic of copolymers were studied by means of advanced analytical techniques such as FT-IR,1H-NMR, DSC, TGA and WAXD. The results show glass transition temperature （Tg） in the range of 193-206℃, thermally stable in excess of 434℃ and excellent solubility in polar solvents. Methyl-substituted Poly（aryl ether sulfone ketone）s had higher glass transition temperatures, lower initial decomposition temperatures than the unsubstituted ones.展开更多
A benign approach for efficient preparation of poly（ether sulfone） （PES） （η_inh = 0.10-0.31 dL.g^-1） has been presented by using ionic liquid （IL）/zwitterion （ZI） as reaction medium. It has been found that ...A benign approach for efficient preparation of poly（ether sulfone） （PES） （η_inh = 0.10-0.31 dL.g^-1） has been presented by using ionic liquid （IL）/zwitterion （ZI） as reaction medium. It has been found that the interaction between 4,4＇- dihydroxydiphenylsulfone （Bisphenol-S） and ZI at elevated temperatures results in efficient reduction of dehydration time, which is confirmed by TGA curves, melting point of the mixture and FTIR spectra. Furthermore, no agglomeration is observed at dehydration stage, which is attributed to the high solubility of Bisphenol-S dipotassium salt in IL/ZI. This also makes the polymerization temperature （150 ℃） much lower than a conventional method （220-300 ℃）. In order to demonstrate the efficiency of IL/ZI as reaction medium, the polymerization was also performed in sulfolane under the same reaction condition as that in IL/ZI.展开更多
A novel engineering thermoplastic, phenolphthalein poly(ether ether sulfone)(PES C) was blended with a commercial thermotropic liquid crystalline polymer(TLCP), Vectra A950, up to 30 weight percent of TLCP. A rheom...A novel engineering thermoplastic, phenolphthalein poly(ether ether sulfone)(PES C) was blended with a commercial thermotropic liquid crystalline polymer(TLCP), Vectra A950, up to 30 weight percent of TLCP. A rheometrics dynamic spectrometer (RDS Ⅱ) and a CEAST capillary rheometer, a rheoscope 1000 were employed to investigate the melt rheology and extrusion behaviour at both the low and high shearing rates. The morphologies of the blends under different shearing were observed with a scanning electron microscope(SEM) and correlated to the observed rheology. The principal normal stress differences measured with cone and plate geometry give a temperature independent correlation for both blend and PES C when they are plotted against shear stress. But the extrudate swell of the blends showed a strong temperature dependence at each shear stress. The concentration dependence of extrudate swell shows a contrary behaviour to that of the inorganic filled system. A reasonable hypothesis based on the relaxation and disorientation of TLCP during flowing in the capillary and exiting was given to explain it. The melt fracture was checked after extrusion from capillary and was discussed.展开更多
基金Supported by the State Key Development Program for Basic Research of China （2008CB617502）, the National Natural Science Foundation of China （20606025）, and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0641）.
文摘A sulfonated poly（ether ether ketone） （SPEEK） membrane with a fairly high degree of sulfonation （DS） can swell excessively and even dissolve at high temperature. To solve these problems, insolvable functionalized silica powder with sulfonic acid groups （SiOx-S） was added into the SPEEK matrix （DS = 55.1%） to prepare SPEEK/ SiOx-S composite membranes. The decrease in both the swelling degree and the methanol permeability of the membranes was a dose-dependent result of addition of the SiOx-S powder. Pure SPEEK membrane swelled 52.6% at 80℃, whereas the SPEEK/SiOx-S （15%, by mass） membrane swelled only 27.3% at the same temperature. From room temperature to 80℃, all SPEEK/SPEEK/SiOx-S composite membranes had methanol permeability of about one order of magnitude lower than that ofNafion115. Compared with pure SPEEK membranes, the addition of the SiOx-S powder not only leads to higher proton conductivity, but also increases the dimensional stability at higher temperatures, and greater proton conductivity can be achieved at higher temperature. The SPEEK/SiO4-S （20%, by mass） membrane could withstand temperature up to 145℃, at which in 100% relative humidity （RH） its proton conductivity exceeded slightly that of Nafion 1 15 membrane and reached 0.17 S·cm^-1, while pure SPEEK membrane dissolved at 90℃. The SPEEK/SiOx-S composite membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.
基金Supported by the State Key Development Program for Basic Research of China （2008CB617502）, the National Natural Science Foundation of China （20606025）, and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0641）.
文摘A sulfonated poly（ether ether ketone） （SPEEK） membrane with fairly high degree of sulfonation （DS） swells excessively and even dissolves at high temperature. To solve these problems, sulfonated phenolphthalein poly（ether sulfone） （SPES-C, DS= 53.7%） is blended with the SPEEK matrix （DS= 55.1%, 61.7%） to prepare SPEEKJSPES-C blend membrane. The decrease in swelling degree and methanol permeability of the membrane is dose-dependent. Pure SPEEK （DS = 61.7%） membrane dissolves completely in water at 70℃, whereas the swelling degree of the SPEEK （DS = 61.7%）/SPES-C （40%, by mass） membrane is 29.7% at 80℃. From room temperature to 80℃, the methanol permeability of all SPEEK （DS = 55.1%）/SPES-C blend membranes is about one order of magnitude lower than that of Nafion 115. At higher temperature, the addition of SPES-C polymer increases the dimensional stability and greater proton conductivity can be achieved. The SPEEK （DS = 55.1%）/SPES-C （40%, by mass） membrane can withstand temperatures up to 150℃. The proton conductivity of SPEEK （DS = 55.1%）/SPES-C （30%, by mass） membrane approaches 0.16 S·cm^-1, matching that of Nafion 115 at 140℃ and 100% RH, while pure SPEEK （DS = 55.1%） membrane dissolves at 90℃. The SPEEK/SPES-C blend membranes are promising for use in direct methanol fuel cells because of their good dimensional stability, high proton conductivity, and low methanol permeability.
基金supported by the Natural Science Foundation of Liaoning Province of China(No.20041076)
文摘Sulfonated poly（ether ketone）s containing 3,5-dimethyl phthalazinone moieties （SPPEK-DMs） with different degrees of sulfonation （DS） were synthesized via direct polycondensation from 4-（3,5-dimethyl-4-hydroxyphenyl）-2,3- phthalazinone, 4,4＇-difluorobenzophenone and 3,3＇-disulfonate-4,4＇-difluorobenzophenone. The chemical structure of SPPEK-DMs was characterized by FTIR and 1H-NMR. Thermal stability of SPPEK-DMs was characterized by the thermogravimetric analysis. The membranes prepared from SPPEK-DMs exhibited ion exchange capacities （IEC） ranging from 0.93 mmol.g-1 to 1.86 mmol.g-1. Water uptake, swelling, oxidative stability and methanol permeability of SPPEK- DMs membranes were investigated. SPPEK-DMs membranes exhibited high oxidative stability. The methanol permeability values of SPPEK-DMs membranes were in the range 5.15× 10^-8-6.61×10^-7 cm^2.s-1, which was much lower than those of Nafion117. The proton conductivity of SPPEK-DM40 membranes was 1.1 ×10^-2 S.cm^-1 at 70℃.
基金This work was financially supported by the National Science Foundation of China (NSFC) (Key project, No. 29734120)the China High-Tech Development 863 Program (No. 2003AA302410)+1 种基金Natural Science Foundation of Guangdong Province (Excellent Team Project, No. 015007)Canton Province Sci & Tech Bureau (Key Strategic Project, No. A1100402) and Guangzhou Sci & Tech Bureau
文摘A novel sulfonated poly（arylene ether） containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place at the para position of the pendant phenyl rings because of the specially designed parent polymer. The position and degree of sulfonation were characterized by ^1H-NMR and elemental analysis. The sulfonated polymers are highly soluble in common organic solvents, such as dimethylsulfoxide, N,N＇-dimethylacetamide, dimethylformamide, ethylene glycol monomethyl ether, and can be readily cast into tough and smooth films from solutions. The films showed good thermal and hydrolysis stabilities. Moreover, Fenton＇s reagent test revealed that the films exhibited superior stability to oxidation. The proton conductivities of the films were comparable with Nation 117 under same conditions. The membrane electrode assembly （MEA） prepared with the asmade film （706 EW, 100 μm dry thickness） shows better cell performance than Nation 115-MEA in the whole current density range.
基金support of the National Natural Science Foundation of China(Nos. 21603197, 21703212,21233006 and 21473164)Natural Science Foundation of Hubei Province of China(No.2016CFB181)+1 种基金Fundamental Research Funds for the Central University, China University of Geosciences (Wuhan)(No. CUGL180403)China University of Geosciences (Wuhan) for the program of Center for Advanced Energy Research and Technologies
文摘Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.
基金This project is supported by the National Natural Science Foundation of China(No.20104001).
文摘N,N＇-Bis（3-hydroxyphenyl）-1,8,4,5-naphthalenetetracarboxylic bisimide was prepared from the reaction of 1,8,4,5-naphthalenetetrcarboxylic acid dianhydride and 2-aminophenol in N, N-dimethylformamide. Polymerization of this bisimide with 4,4＇-difluorodiphenylsulfone and disodium 3,3＇-disulfonate4,4＇-difluorodiphenylsulfone gave ion-exchange sulfonated poly（ether sulfone）. The structure of the title compound was characterized with H-NMR and its polymer was characterized with FT-IR.
基金financially supported by the National Natural Science Foundation of China(No.21306010)。
文摘A series of multiblock sulfonated poly(arylene ether sulfone)s(SPAES)with various block lengths and predictable ion exchange capacity were synthesized from 4,4’-difluorodiphenyl sulfone,4,4’-dihydrodiphenyl sulfone and 4,4’-biphenol by one-pot and two-pot polymerization.;H-NMR and FTIR spectra confirmed the structure that sulfonic acid groups were introduced precisely on the poly(arylene ether sulfone)s by post-sulfonation which resulted in controllable sulfonation degree.The proton exchange membranes(PEMs)-based SPAES displayed excellent dimensional,thermal,antioxidant stability,proton conductivity and mechanical properties(maximum tensile stress>35 MPa).Thermogravimetric analysis indicated the prepared SPAES began to degrade above 310℃.The effects of polymerization processes,those were,one-pot hydrophobic segment process,one-pot hydrophilic segment process and two-pot process,on the properties of polymers were investigated.The proton conductivity and microphase separation of SPAES PEMs increased in order of those prepared by one-pot hydrophobic segment process,two-pot process and one-pot hydrophilic segment process.The highest conductivities of SPAES synthesized by the above processes under 80℃ and 100%relative humidity were 213(MS4),297(MB3)and 360 mS·cm^(-1)(MQ2),respectively.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(No.20164030201070)supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT and future Planning(NRF-2017R1A2B4005230)
文摘A ternary hybrid membrane architecture consisting of sulfonated fluorinated multi-block copolymer （SFMC）, sulfonated （poly ether ether ketone） （SPEEK） and I or 5 wt% graphene oxide （GO） was fabricated through a facile solution casting approach. The simple, but effective monomer sulfonation was performed for SFMC to create compact and rigid hydrophobic backbone structures, while conventional random sulfonation was carried-out for SPEEK. Hydrophilic-hydrophobic-hydrophilic structure of SFMC enhances the compatibility with SPEEK and GO and allows for an unprecedented approach to alter me- chanical strength and proton conductivity of ternary hybrid membrane, as verified from universal test machine （UTM） curves and alternating current （AC） impedance plots. The impact of GO integration on the morphology and roughness of hybrid membrane was scrutinized using field emission scanning electron microscope （FE-SEM） and atomic force microscope （AFM）. Ternary hybrid showed uniform intercalation of GO nanosheets throughout the entire surface of membrane with an increased surface roughness of 8.91 nm. The constructed ternary hybrid membrane revealed excellent water absorption, ion exchange capacity and gas barrier properties, while retaining reasonable dimensional stability. The well-optimized ternary hybrid membrane containing 5 wt% GO revealed a maximum proton conductivity of 111.9 mS/cm, which is higher by a factor of two-fold with respect to that of bare SFMC membrane. The maximum PEMFC power density of 528.07mW/cm2 was yielded by ternary hybrid membrane at a load current density of 1321.1 mA/cm2 when operating the cell at 70 ℃ under 100% relative humidity （RH）. In comparison, a maximum power density of only 182.06 mW/cm2 was exhibited by the bare SFMC membrane at a load current density of 455.56 mA/cm2 under same operating conditions.
基金Byoungseok Min of Pohang Accelerator Laboratory for SAXS technical support at 4C beamline.All authors have read the manuscript and agreed to its contents。
文摘Prolonged hydrothermal treatment for sulfonated poly(ether ether ketone) membranes induces mechanical degradation and developing hydrophilic-hydrophobic phase separation, simultaneously. The enhanced phase separation provides incremental proton conductivity to the membranes, whereas mechanical degradation drastically reduces device stability. On this basis, we describe here the effects of two different ex situ aging processes on sulfonated poly(ether ether ketone) membranes: hydrationdehydration cycling and prolonged hydrothermal treatment. Both aged membranes exhibited enhanced phase separation under the hydrated conditions, as characterized by small angle X-ray scattering.However, when the aged membranes were dried again, the nanostructure of the membranes aged via the hydration-dehydration cycling was recoverable, whereas that of the membranes aged via prolonged hydrothermal treatment was irreversible. Furthermore, the two differently aged membranes showed clear differences in thermal, mechanical, and electrochemical properties. Finally, we implemented both aged membranes in fuel cell application. The sample aged via hydration-dehydration cycling maintained its improved cell performance, whereas the sample aged via hydrothermal treatment showed drastically reduced cell performance after durability test for 50 h.
基金partly financed by the Major State Basic Research Development Program of China(No.2003 CB615700)the National Natural Science Foundation of China(No.20604005).
文摘Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.
文摘A novel series of poly（aryl ether sulfone ketone）s （PPESKs） containing phthalazinone and biphenyl moieties were prepared by two-step nucleophilic polycondensation reaction. The ^-Mw values of these copolymers were between 38,330 and 67,900. The glass transition temperatures （Tg） and 5% decomposition temperatures were ranged in 253-269 ℃ and 488-500 ℃, respectively, The structures of these copolymers were confirmed by FT-IR and ^1H NMR. Moreover, all the resultant copolymers were amorphous determined by wide angle X-ray diffraction （WAXD）.
基金the National Natural Science Foundation of China for financial support.
文摘1, 2-Diliydro-4-(4-hydroxyphenyl)(2H)phthalazin-1-one(DHPZ) was sulfonated in concentrated Sulfuric acid. Poly(phthalazinone ether ketone) containing pendant sodium sulfonate group was synthesized from sulfonated and pure 1,2-dihydro-4-(4-hydroxyphenyl)(2H)phthalazin-1-one, and 4,4'-difluorodiphenylketone. The sulfonated monomer and sulfonated polymer were characterized with FT-IR and H-1-NMR.
基金financial support under Heilongjiang Postdoctoral Fund (No.LBH-Z09175)
文摘Novel poly（aryl ether sulfone ketone）s （PAESK） were synthesized from bisphenol A （BPA）, 9,9＇-bis（4-hydroxyphenyl） fluorene （BHPF）, 4,4＇-dichlorodiphenylsulfone （DCS） and 4,4＇-difluorobenzophenone （DFB） via nucleophilic substitution polymerization, which were subsequently used to fabricate ultrafiltration membrane by phase-inversion method for high temperature condensed water treatment. The obtained high molecular weight co-polymers with fluorene group with good solubility and good thermal stability, can be easily cast into flexible, white and non-transparent fiat films. The influence of molar ratio of BPA and BHPF on the properties of the prepared co-polymers and membranes was investigated in detail. SEM study of the morphology of the membranes indicated that the prepared membranes possessed homogeneous pores on the top surface and were sponge-like or finger-like in cross-section. Pure water flux of the membranes increased from 71.87 L·m-2.h-1 to 247.65 L·m-2.h-1, while the retention of BSA decreased slightly, and the water contact angle decreased from 82.1 ° to 55.6° with the PVP concentration from 0 wt% to 10 wt%. With increasing concentration of PVP, the mechanical properties of membranes decreased, while the thermal stability increased. The permeate flux measurement showed that the PAESK membrane had the potential for high temperature condensed water treatment.
基金Supported by the National Natural Science Foundation of China(No.50973040)the Science and Technology Development Plan of Jilin Province, China(No.20090322)
文摘A novel type of crosslinkable poly（aryl ether sulfone）（PAES） bearing an allyl pendant（PES-OAllyl） was synthesized by a grafting reaction of hydrophenyl-containing PAES（PES-OH） and allyl bromide. PES-OH was prepared by a demethylation reaction of a methoxyphenylated PAES（PES-OCH3） in the presence of pyridine/hydrochlo- ride. The PES-OCH3 was synthesized by an aromatic nucleophilic substitution of bis（4-chlorophenyl）sulfone and （p-methoxy）phenylhydroquinone. Both DSC and solubility investigation were used to study the crosslinking behavior of PES-OAllyl. After heat treatment, the glass transition temperature（Tg） value of PES-OAllyl sharply increased from 165 ℃ to 227 ℃. Meanwhile, PES-OAllyl changed from a soluble polymer to an insoluble thermoset. In addition, TGA（thermogravimetric analysis） result suggests that the thermal stability of the crosslinked product was improved. All the data prove that the crosslinked PES-OAllyl could be a potential solvent-resistance high-performance material.
基金financially supported by the National Natural Science Foundation of China(No.51203151)the Program of Jilin Education Department(No.93201201)
文摘A series of cardo poly（aryl ether sulfone） copolymers bearing pendent sulfonic acid groups （SPES-X） have been prepared by a facile chemical graft method. The structure was confirmed by 1H-NMR spectra. The side-chain-type SPES-X membranes show significantly reduced swelling behavior and excellent mechanical properties as well as appropriate proton conductivity compared to the main-chain-type sulfonated polymers with similar ion exchange capacity （IEC） value. Moreover, they show methanol permeability in the range of 0.6 × 10^-7-5.7 × 10^-7 cmE/s which is lower than that of Nafion 117. All the results indicate that the SPES-Xmembranes are promising candidates for the direct methanol fuel cells.
基金supported by the national natural science foundation of China(59473019).
文摘A novel poly(ether sulfone ketone)containing the phthalazinone moiety was prepared by the reaction of4-)4-hydroxyphenyl)(2H)phthalazin-1-one with activated dichloro-monomers.The polymer was characterized by FT-IR,H-1-NMR,DSC,TGA and X-ray diffraction.
基金This work was supported by National Science Foundation of China （No. 20264001 ）, National Science Foundation of Jiangxi Province, Innovation Fund for Technology Based Firms of China （No. 06C26213601342）.
文摘A series of Poly（arly ether sulfone ether ketone）s containing pendant methyl groups were synthesized by the reaction of 4,4＇-[sulfonylbis （1,4-phenylene）dioxy] dibenzoyl chloride （SODBC） with 4,4＇- diphenoxy diphenylsulfone （DPODPS）, 4,4＇- di（2-methylphenoxy） diphenylsulfone （o-Me-DPODPS）, 4,4＇- di（3-methylphenoxy） diphenylsulfone （m-Me-DPODPS）, 4,4＇- di （2,6-bimethylphenoxy） biphenylsulfone（o-Me2-DPODPS） respectively, in a mixture of 1,2-dichloroethane （DCE） and N-methylpyrrolidone （NMP）. These reactions were catalyzed by anhydrous aluminum chloride （AlCl）. The characteristic of copolymers were studied by means of advanced analytical techniques such as FT-IR,1H-NMR, DSC, TGA and WAXD. The results show glass transition temperature （Tg） in the range of 193-206℃, thermally stable in excess of 434℃ and excellent solubility in polar solvents. Methyl-substituted Poly（aryl ether sulfone ketone）s had higher glass transition temperatures, lower initial decomposition temperatures than the unsubstituted ones.
基金financially supported by the National Natural Science Foundation of China(No.21274014)the Fundamental Research Funds for the Central Universities+1 种基金Program for Changjiang Scholars and Innovative Research Team in UniversityMeasuring Fund of Large Apparatus of Beijing Normal University
文摘A benign approach for efficient preparation of poly（ether sulfone） （PES） （η_inh = 0.10-0.31 dL.g^-1） has been presented by using ionic liquid （IL）/zwitterion （ZI） as reaction medium. It has been found that the interaction between 4,4＇- dihydroxydiphenylsulfone （Bisphenol-S） and ZI at elevated temperatures results in efficient reduction of dehydration time, which is confirmed by TGA curves, melting point of the mixture and FTIR spectra. Furthermore, no agglomeration is observed at dehydration stage, which is attributed to the high solubility of Bisphenol-S dipotassium salt in IL/ZI. This also makes the polymerization temperature （150 ℃） much lower than a conventional method （220-300 ℃）. In order to demonstrate the efficiency of IL/ZI as reaction medium, the polymerization was also performed in sulfolane under the same reaction condition as that in IL/ZI.
文摘A novel engineering thermoplastic, phenolphthalein poly(ether ether sulfone)(PES C) was blended with a commercial thermotropic liquid crystalline polymer(TLCP), Vectra A950, up to 30 weight percent of TLCP. A rheometrics dynamic spectrometer (RDS Ⅱ) and a CEAST capillary rheometer, a rheoscope 1000 were employed to investigate the melt rheology and extrusion behaviour at both the low and high shearing rates. The morphologies of the blends under different shearing were observed with a scanning electron microscope(SEM) and correlated to the observed rheology. The principal normal stress differences measured with cone and plate geometry give a temperature independent correlation for both blend and PES C when they are plotted against shear stress. But the extrudate swell of the blends showed a strong temperature dependence at each shear stress. The concentration dependence of extrudate swell shows a contrary behaviour to that of the inorganic filled system. A reasonable hypothesis based on the relaxation and disorientation of TLCP during flowing in the capillary and exiting was given to explain it. The melt fracture was checked after extrusion from capillary and was discussed.
