Sulfone Units Research Articles

Synthesis of sulfonated organic–inorganic hybrids through the radical copolymerization of vinyl sulfonate esters and vinyl trialkoxysilanes

Novel organic–inorganic hybrids with sulfonic acid groups were prepared using random copolymers composed of vinyl sulfonate esters and vinyl trialkoxysilanes. Five vinyl sulfonate esters with different substituent groups were employed as protecting monomers for the production of the poly(vinyl sulfonic acid) component, and three vinyl trialkoxysilanes were used as cross-linkable monomers. Free radical and reversible addition-fragmentation chain transfer (RAFT) copolymerizations were performed for the production of random copolymers with two different functional groups. The selective deprotection of the sulfonate esters of the copolymers proceeded smoothly and resulted in the formation of copolymers with lithium vinyl sulfonate units and cross-linkable trialkoxysilane units. The co-condensation of the trialkoxysilane moieties in the deprotected copolymers with cross-linkers yielded transparent hybrid films that contained lithium sulfonate groups without aromatic rings or ester linkages.

Synthesis and properties of polyamides derived from 4,6-bis(4-chloroformylphenylthio)pyrimidine and 3,6-bis(4-chloroformylphenylthio)pyridazine

Two kinds of monomers containing thioether units 4,6-bis(4-chloroformylphenylthio)pyrimidine (BPPM-DC) and 3,6-bis(4-chloroformylphenylthio)pyridazine (BPPD-DC) were synthesized by two steps and were reacted with diamine-containing thioether (−S–) and sulfone units to prepare a kind of polyamide containing heterocycles and high contents of thioether groups. These polyamides had good optical properties, including an optical transmittance of the aromatic polyamide film at 450 nm that was higher than 87%. Additionally, the pyridazine, pyrimidine and the large quantity of thioether units provided the polymers with high refractive indices of 1.722–1.732 and low birefringences of 0.004–0.006. These polyamides were also found to have good thermal properties. They showed improved solubility in polar aprotic solvents and could form tough films with a tensile strength of 79.2–112.3 MPa and a storage modulus of 1.4–2.4 GPa (at 200 °C).© 2013 Society of Chemical Industry

Photoswitchable fluorescent diarylethene derivatives with short alkyl chain substituents

The sulfone derivatives of 1,2-bis(2-alkyl-6-phenyl-1-benzothiophen-3-yl)perfluorocyclopentene having various short alkyl chain substituents at reactive carbons were prepared and the effect of alkyl substitution on the fluorescence property of the closed-ring isomers was studied. Upon irradiation with ultraviolet (UV) light the derivatives exhibit a brilliant green fluorescence under irradiation with visible (> 400 nm) light, while the fluorescence disappears upon irradiation with visible (> 400 nm) light alone. The fluorescence quantum yield of the methyl substituted derivative (1b) dramatically decreases from 0.84 to 0.15 when the solvent is changed from hexane to acetonitrile, while the changes of ethyl, n-propyl and n-butyl substituted derivatives (2b)–(4b) are moderate. The quantum yields of (2b)–(4b) are kept to values close to 0.7 even in polar acetonitrile. The fluorescence lifetime measurement revealed that efficient non-radiative decay processes took place in (1b) in polar solvent, while their contribution to the deactivation was not so large in (2b)–(4b). The neighboring short alkyl chains at the connecting carbons are considered to defend the sulfone units against the attack of polar solvent molecules and weaken the solvent polarity effect.

Development of Cu2+- and/or phosphonium-based polymeric biocidal materials and their potential application in antifouling paints

The synthesis and characterization of a series of biocidal polymeric materials for potential antifouling submarine applications are presented. The polymeric backbone of these materials contains anionic units, such as styrene sulfonate, and/or acrylate or maleate units. The hydrophobic/hydrophilic nature of these polymers was, furthermore, tuned through copolymerization with hydrophobic units, such as vinyl acetate or styrene. The biocidal species, Cu2+ ions and/or phosphonium cations, were incorporated through electrostatic and/or coordination interactions, depending on the nature of the polymeric backbone. It was observed that the release of Cu2+ ions in water from the Cu2+-containing materials is controlled by the hydrophobic/hydrophilic balance of the polymeric backbone. The prepared biocidal polymeric materials were incorporated into two paint formulations, based on a rosin or a vinylic matrix. The erosion properties of the biocidal paints under accelerated laboratory conditions were evaluated using scanning electron microscopy. It is found that the antifouling performance is related to the release of biocidal species. The most efficient materials are those containing Cu2+ ions or combining both Cu2+ and phosphonium cations.

Block poly(arylene ether sulfone ketone)s containing densely sulfonated linear hydrophilic segments as proton conductive membranes

Synthesis and properties of aromatic block copolymers composed of highly sulfonated phenylene ether sulfone ketone units as hydrophilic blocks and phenylene ether biphenyene sulfone units as hydrophobic blocks are reported. High molecular weight block copolymers 4 (Mw = 275–362 kDa and Mn = 76–144 kDa) with different compositions (number of repeat unit in the hydrophobic blocks (X) = 15, 30, or 60, and that of hydrophilic blocks (Y) = 4, 8, or 12) were synthesized. Transparent and bendable membranes were obtained by casting from the solution of 4. Due to the rigid rod-like structure of the hydrophilic blocks, the nanophase-separated morphology was not as distinct as that of the conventional sulfonated aromatic block copolymer membranes. Highly sulfonated hydrophilic blocks, which contained phenylene rings with sulfonic acid groups and electron-withdrawing sulfone or ketone groups, contributed to the high proton conductivity and improved oxidative stability of 4 membranes. The 4 (X60Y12) membrane with low IEC (1.18 mequiv g−1) showed comparable or higher conductivity than that of Nafion at >80% relative humidity (RH).

Novel Ferrocene-Based Organometallic Poly(ether sulfone amide imide)s: Preparation, Characterization, and Properties

A new ferrocene-based diamine (ESAFDA) with built-in ether, sulfone, and amide groups was prepared via reaction of two synthetic precursors. Firstly, 1,1′-ferrocenedicarbonyl chloride was prepared from 1,1′-ferrocenedicarboxylic acid using oxalyl chloride. In another reaction, nucleophilic substitution reaction of 3-aminophenol with bis(4-chlorophenyl sulfone) was used for synthesis of 3,3′-(4,4′-sulfonyl bis(1,4-phenylene) bis (oxy)) dianiline (SBOD). Finally, the diamine was prepared via nucleophilic reaction of SBOD with 1,1′-ferrocenedicarbonyl chloride. The precursors and the diamine were characterized by conventional methods and the diamine was used for preparation of different ferrocene-based poly(ether sulfone amide imide)s through polycondensation with three different dianhydrides. The polymers were characterized by elemental analysis, FTIR and 1H-NMR spectroscopy. Various properties of the polymers including inherent viscosity, molecular weight, solubility, thermal stability and behavior, flame-retardant nature, mechanical properties, and crystallinity were studied. Presence of ferrocene structure in companion to ether, sulfone, and amide units in the backbone of polyimides led to improved solubility of the polymers in polar aprotic solvents and enhanced thermal stability and flame-retardant character of polyimides.

Synthesis and properties of polyamides containing high contents of thioether units

Two kinds of monomers containing the thioether units 4,4′-thiodibenzoyl chloride (T-DC) and 4,4′-bis(4-chloroformylphenylthio)benzene (BPB-DC) were synthesized in two steps and were reacted with diamine-containing thioether (–S–) and sulfone units to prepare a polyamide containing high contents of thioether groups. The intrinsic viscosities of the polyamides were 0.81–0.93 dl/g. These polymers had good optical properties, including an optical transmittance of the aromatic polyamide film at 450 nm that was higher than 90%. Additionally, the high quantity of thioether units provided the polymers with high refractive indices of 1.710–1.716 and low birefringences of 0.007–0.009. These polyamides also had excellent thermal properties, with glass transition temperatures ( T g ) of 230–246 °C and initial degradation temperatures ( T d ) of 477–473 °C. Finally, they showed improved solubility in polar aprotic solvents.

Sulfonated poly(arylene ether sulfone) ionomers containing di- and tetrasulfonated arylene sulfone segments

Poly(arylene ether sulfone) (PSU) ionomers containing disulfonated aryl-SO2-aryl and tetrasulfonated aryl-SO2-aryl-aryl-SO2-aryl segments, respectively, were synthesized and studied to establish their structure–property relationships as proton-exchange membranes. High molecular weight PSUs with different distributions of sulfone bridges in the backbone were prepared by nucleophilic aromatic substitution reactions involving 4,4′-dichlorodiphenyl sulfone (DCDPS), 4,4′-bis[(4-chlorophenyl)sulfonyl]-1,1′-biphenyl (BCPSB), 4,4′-isopropylidenediphenol (bisphenol A), and 4,4′-(1,4-phenylenediisopropylidene)bisphenol (bisphenol P). The polymers were sulfonated viametallation and reaction with sulfur dioxide, followed by oxidation of the resulting sulfinates. This procedure allowed the introduction of two sulfonic acid units on electron-deficient aryl rings in ortho positions to each sulfone bridge of the PSUs. Analysis by small angle X-ray scattering of solvent cast membranes showed that ionic clustering was promoted in ionomers containing sulfonated BCPSB residues and flexible bisphenol P residues. The fully sulfonated PSUs had ion-exchange capacities (IECs) of 3.3–4.1 meq g−1 and were water soluble. However, partly sulfonated polymers with IECs of approx. 1.7 meq g−1 showed high proton conductivity at moderate water uptake and decomposed only above 240 °C during heating 1 °C min−1 under air. This work demonstrated that BCPSB residues can be conveniently and fully tetrasulfonated, which opens possibilities to prepare various aromatic copolymers and membranes with locally very high densities of hydrolytically stable sulfonic acid groups.

Irradiated PVdF-HFP-montmorillonite composite membranes for the application of direct ethanol fuel cells

Montmorillonite supported poly vinylidene fluoride–hexa fluoro propylene composite membranes have been functionalized by an irradiation technique for the application of direct ethanol fuel cells. Structural characterizations of the fabricated membranes are examined by infrared and X-ray photoelectron spectroscopy analyses. The montmorillonite particles reduce porosity and stimulate rough nature to the PVdF-HFP membrane. Thermal stability of the irradiated membranes gets increased by the restricted polymeric segmental motion given via the montmorillonite particles. The ion exchange capacity values purely depend on the grafting degree values whereas water uptake values are influenced by the grafting degree as well as the concentration of montmorillonite particles. Irrespective of the grafting degree values, the adsorbed water molecules dissociate sulfonic acid units in a greater extent and favor ionic conductivity values. Tortuous path ways generated by the montmorillonite particles distort the molecular permeation which in turn results in the lower fuel cross over. By the synergistic combination of irradiation and nanocomposite techniques, demerits of the aforementioned individual techniques have been effectively tackled which in turn results in the extended direct ethanol fuel cell efficiencies of the fabricated fuel cell membranes and emerges its large scale applications.

Copoly(arylene ether nitrile) and copoly(arylene ether sulfone) ionomers with pendant sulfobenzoyl groups for proton conducting fuel cell membranes

Three series of fully aromatic ionomers with naphthalene moieties and pendant sulfobenzoyl side chains were prepared via K2CO3 mediated nucleophilic aromatic substitution reactions. The first series consisted of poly(arylene ether)s prepared by polycondensations of 2,6-difluoro-2'-sulfobenzophenone (DFSBP) and 2,6-dihydroxynaphthalene or 2,7-dihydroxynaphthalene (2,7-DHN). In the second series, copoly(arylene ether nitrile)s with different ion-exchange capacities (IECs) were prepared by polycondensations of DFSBP, 2,6-difluorobenzonitrile (DFBN), and 2,7-DHN. In the third series, bis(4-fluorophenyl)sulfone was used instead of DFBN to prepare copoly(arylene ether sulfone)s. Thus, all the ionomers had sulfonic acid units placed in stable positions close to the electron withdrawing ketone link of the side chains. Mechanically strong proton-exchange membranes with IECs between 1.1 and 2.3 meq g(-1) were cast from dimethylsulfoxide solutions. High thermal stability was indicted by high degradation temperatures between 266 and 287 degrees C (1 degrees C min(-1) under air) and high glass transition temperatures between 245 and 306 degrees C, depending on the IEC. The copolymer membranes reached proton conductivities of 0.3 S cm(-1) under fully humidified conditions. At IECs above similar to 1.6 meg g(-1), the copolymer membranes reached higher proton conductivities than Nafion (R) in the range between -20 and 120 degrees C. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 734-745, 2011 (Less)

Synthesis of the Sulfonate Analogue of Seminolipid via Horner−Wadsworth−Emmons Olefination

The first synthesis of the sulfonate analogue of seminolipid, the main sulfoglycolipid in mammalian sperm, is reported. Installation of the sulfonate unit was accomplished by a quite unexplored strategy based on Horner-Wadsworth-Emmons olefination on a 3 '-keto-galactoside, followed by stereoselective double bond reduction.

Synthesis and characterization of organo-soluble thioether-bridged polyphenylquinoxalines with ultra-high refractive indices and low birefringences

Two aromatic tetraketones, 4,4′-thiobis[(p-phenyleneoxy)benzil] (STK, 1) and 4,4′-thiobis[(p-phenylenesulfanyl)benzil] (3STK, 2) were synthesized by the nitro nucleophilic substituent reactions of 4-nitrobenzil and corresponding diol compounds. The two tetraketones were polymerized with three aromatic tetraamines, including 3,3′-diaminobenzidine (a), 3,3′,4,4′-tetraaminodiphenylether (b) and 3,3′,4,4′-tetraaminodiphenylsulfone (c), respectively to afford six thioether-bridged polyphenylquinoxalines (PPQs) – PPQ-1a–1c and PPQ-2a–2c. The obtained PPQs exhibited good solubility not only in conventional m-cresol and chloroform, but in the aprotic solvent – N-methyl-2-pyrrolidinone (NMP). PPQ-1c and 2c containing sulfone units were even soluble in tetrahydrofuran at room temperature with a solid content of 15 wt%. Flexible and tough PPQ films cast from their NMP solution showed good thermal stabilities, including glass transition temperatures in the range of 215–248 °C and 5% weight loss temperatures exceeding 500 °C in nitrogen. The PPQ films at a thickness of ∼10 μm exhibited moderate optical transparency at 450 nm. The best optical transmittance around 80% was achieved by PPQ-1c and 2c containing electron-withdrawing sulfone moieties. The synergic effects of flexible thioether linkages and highly conjugated quinoxaline rings in the present PPQs endowed them with ultra-high refractive indices up to 1.7953 at 632.8 nm and birefringences close to zero.

Ring-Opening Reactions within Porous Metal−Organic Frameworks

Two new metal-organic framework (MOF) structures, IRMOF-3b and -3c, were prepared by ring-opening reaction of 1,3-propanesultone and 2-methylaziridine with an amine functionalized MOF, IRMOF-3. The new structures are permanently functionalized with covalently linked sulfonate and alkyamine units, respectively. The underlying framework structure is retained after reaction as confirmed by powder X-ray diffraction. The high porosity of IRMOF-3 is also maintained, as evidenced by nitrogen adsorption experiments, which yield Brunauer-Emmett-Teller (BET) surface areas of 1380 and 530 m(2) g(-1) compared to 2040 m(2) g(-1) in the parent material. Ring-opening reactions provide a versatile route to irreversible binding of a range of functionalities that are otherwise difficult to access in MOFs.

Changing the Overall Shape of Heterodinuclear Helicates via Substitution of Acylhydrazones by Tosylhydrazones

Heterodinuclear helicate-type complexes are formed from acyl and tosyl hydrazone-substituted catechol ligands. Due to the different geometry of the carboxylate compared to the sulfonate unit, different overall structures are observed for the complexes. The acylate results in the formation of a cylindrical triple-stranded system, while in the tosylate the pendant substituents fold back and form a more condensed structure.

High‐Yield Synthesis and Crystal Structure Determination of Sodium Triphenylphosphane Monosulfonate (TPPMSNa)

AbstractA simple, high‐yield synthesis is described that leads tothe sodium salt of monosulfonated triphenylphosphane (TPPMSNa) as a pure product in large quantities without complicated workup techniques. The single‐crystal X‐ray structure of TPPMSNa·2.5H2O is reported. The structure is built up by alternating layers of aquated sodium sulfonate units and hydrophobic triphenyl units. Thermogravimetric analyses show the loss of one molecule of water at 70 and one at 105 °C. Thermal decomposition occurs at temperatures above 400 °C. The anhydrous ligand is hygroscopic. The preparation of the free acid TPPMSH starting from the sodium salt is also reported. TPPMSH is an extremely hygroscopic solid that could not be isolated in the crystalline form.

Mesoscopic simulation of an ionomeric membrane based on sulfonated aromatic poly(ether ether ketone)

Mesoscopic simulation in the framework of the mesoscopic dynamics method (a version of the dynamic density functional method) was performed for a proton conducting membrane based on sulfonated aromatic poly(ether ether ketone) in a wide range of water content in the system. For the selected parametric field, the model demonstrates microphase separation of hydrophilic and hydrophobic segments of the polymer. In the bulk of the membrane, a spatial network of water channels forms, whose walls consist of polar (sulfonated) units of the macromolecule. Independent molecular dynamics simulation for one set of parameters gives close values of the structural characteristics of the membrane, which confirms the correctness of the mesoscopic model.

Synthesis of amorphous copoly(thioether sulfone)s with high refractive indices and high Abbe numbers

New thermoplastic random copoly(thioether sulfone)s with high refractive indices and high Abbe numbers have been developed by the simultaneous introduction of sulfide, sulfone, and alicyclic units in the polymer chains. They were prepared by random copolymerization of 2,5-bis(sulfanylmethyl)-1,4-dithiane (BMMD) and cyclohexane-1,4-dithiol (CHDT) with divinyl sulfone (DVS) based on the Michael polyaddition. Tough, flexible, colorless and transparent copoly(thioether sulfone) (poly(BMMD/CHDT–DVS)) films were obtained, and they showed good thermal stability with the 5% weight-loss at temperatures over 300 °C in nitrogen, and the glass transition temperatures of 42–50 °C. The inherent amorphous nature of films was confirmed by differential scanning calorimetry. Poly(BMMD/CHDT–DVS) exhibited quite high level of refractive indices and Abbe numbers as thermoplastics, in the range of 1.6512–1.6022 and 42.6–50.6, respectively. The experimental refractive indices and their wavelength dispersions were well reproduced by the DFT calculations with the aid of empirical density prediction.

Synthesis and characterization of soluble aromatic azopolyamides containing sulfone and ether units

A series of new polyamides 3a–d containing aryl-azo, ether and sulfone groups in the main chain were synthesized from bis[4-(4-aminophenoxy)phenyl sulfone] 1 and several azo aromatic diacyl chlorides 2a–d by the low temperature solution polycondensation technique. FTIR spectroscopy, nuclear magnetic resonance (NMR) and elemental analyses confirmed the structure of these polymers. Owing to the aryl and amide groups in the main chain, these polymers exhibit photochromic properties as well as excellent thermal stabilities. The transition temperatures (Tg) are between 242 and 265 °C, and the char yields at 800 °C in nitrogen atmosphere were above 39%. Based on incorporation of flexible ether linkages and polar sulfone groups, the polyamides show desirable solubility in organic solvents such as DMAc, N,N-dimethylformamide (DMF), N-methyl-2-pyrroidinone (NMP) and dimethylsulfoxide (DMSO). And it is exemplified that polyamide containing 2 and 2′ substitutes performed better solubility.

Locally sulfonated poly(ether sulfone)s with highly sulfonated units as proton exchange membrane

AbstractNovel locally sulfonated poly(ether sulfone)s with highly sulfonated units were successfully synthesized for fuel cell applications. Poly(ether sulfone)s were prepared by the nucleophilic substitution of bis(4‐fluorophenyl) sulfone with 1,2,4,5‐tetrakis([1,1′‐biphenyl]‐2‐oxy)‐3,6‐bis(4‐hydroxyphenoxy)benzene and bis(4‐hydroxyphenyl) sulfide, followed by oxidation using m‐chloroperoxybenzoic acid. The desired highly sulfonated units were easily introduced by postsulfonation and each one had ten sulfonic acid groups. The sulfonated polymers gave tough, flexible, and transparent membranes by solvent casting. The high contrast in polarity between highly sulfonated units and hydrophobic poly(ether sulfone) units enabled the formation of defined phase‐separated structures and well‐connected proton paths. The sulfonated polymers exhibited excellent proton conductivity over a wide range of relative humidities. The proton conductivity of the sulfonated polymer with an ion exchange capacity value of 2.38 mequiv/g was comparable to that of Nafion 117 even at 30% relative humidity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3444–3453, 2009

Highly Sulfonated Poly(phenylene sulfone): Preparation and Stability Issues

This paper presents a preparation route which allows the formation of a poly(phenylene) ionomer containing merely sulfone units (−SO2−) connecting the phenyl rings and in which each phenyl ring is monosulfonated (100% degree of sulfonation). This corresponds to an ion exchange capacity (IEC) of 4.5 mequiv g−1 (equivalent weight of EW = 220 g equiv−1). The preparation succeeded in a two-step process comprising a polycondensation reaction of sulfonated difluorodiphenyl sulfone with sodium sulfide, yielding sulfonated poly(phenylene sulfide sulfone), and the subsequent oxidation to the corresponding sulfonated poly(phenylene sulfone). The polymer was characterized by elemental analysis, NMR, IR, GPC, viscosity measurement, TGA in air and in pure water vapor atmosphere, DSC at low and high temperatures, and ac impedance spectroscopy. Room temperature water absorption isotherms have been determined by equilibrating samples at different relative humidities. Under the chosen reaction conditions, polymers with mo...