Synthesis and properties of copolymers of poly(ether ether sulfone)/semiaromatic polyamides (PEES/PA)

Poly(ether ether sulfone) (PEES) containing semi‐aromatic polyamides with methylene units and ether linkage were synthesized through the copolymerization of m‐dihydroxybenzene, 4,4‐dichlorodiphenylsulfone (DCDPS) and 1,6‐N, N′‐bis(4‐fluorobenzamide) hexane (BFBH) by the method of nucleophilic polymerization. The inherent viscosities of the resultant different proportion of copolymers were in the range of 0.39–0.78 dL/g. These copolymers were found to have excellent thermal properties with glass transition temperatures (T_g) of 121–177°C, and initial degradation temperatures (T_d) of 417.5–432.5°C. These copolymers showed good mechanical properties with tensile strengths of 45–83 MPa, storage modulus of 1.8–2.6 GPa. The complex viscosities of pure Poly(ether ether sulfone) (PEES) was in the range of 176,000–309.8 Pas from 0.01 to 100 Hz, the complex viscosities of the copolymers decreased significantly with the increase of semi‐aromatic amide content, the copolymers of 20% decreased from 4371 to 142.4 Pas (from 0.01 to 100 Hz), and the copolymers of 70% dropped from 634.6 Pas to 55.97 Pas (from 0.01 Hz to 100 Hz). All copolymers exhibited non‐Newtonian and shear‐thinning behavior. These results suggested the resultant copolymers possess better melt flowability that is beneficial for the materials’ melt processing. POLYM. ENG. SCI., 56:44–50, 2016. © 2015 Society of Plastics Engineers     

Enhanced fracture toughness of epoxy resins with novel amine‐terminated poly(arylene ether sulfone)–carboxylic‐terminated butadiene‐acrylonitrile–poly(arylene ether sulfone) triblock copolymers

Amine‐terminated poly(arylene ether sulfone)–carboxylic‐terminated butadiene‐acrylonitrile–poly(arylene ether sulfone) (PES‐CTBN‐PES) triblock copolymers with controlled molecular weights of 15,000 (15K) or 20,000 (20K) g/mol were synthesized from amine‐terminated PES oligomer and commercial CTBN rubber (CTBN 1300x13). The copolymers were utilized to modify a diglycidyl ether of bisphenol A epoxy resin by varying the loading from 5 to 40 wt %. The epoxy resins were cured with 4,4′‐diaminodiphenylsulfone and subjected to tests for thermal properties, plane strain fracture toughness (K_IC), flexural properties, and solvent resistance measurements. The fracture surfaces were analyzed with SEM to elucidate the toughening mechanism. The properties of copolymer‐toughened epoxy resins were compared to those of samples modified by PES/CTBN blends, PES oligomer, or CTBN. The PES‐CTBN‐PES copolymer (20K) showed a K_IC of 2.33 MPa m^0.5 at 40 wt % loading while maintaining good flexural properties and chemical resistance. However, the epoxy resin modified with a CTBN/8K PES blend (2:1) exhibited lower K_IC (1.82 MPa m^0.5), lower flexural properties, and poorer thermal properties and solvent resistance compared to the 20K PES‐CTBN‐PES copolymer‐toughened samples. The high fracture toughness with the PES‐CTBN‐PES copolymer is believed to be due to the ductile fracture of the continuous PES‐rich phases, as well as the cavitation of the rubber‐rich phases. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1556–1565, 2002; DOI 10.1002/app.10390     

Synthesis and characterization of soluble copoly(arylene ether sulfone phenyl-s-triazine)s containing phthalazinone moieties in the main chain

A series of new poly(arylene ether sulfone phenyl-s-triazine) copolymers containing phthalazinone moieties in the main chain (PPESPs) were prepared by a direct solution polycondensation of 4-(4-hydroxylphenyl)(2H)-phthalazin-1-one (HPPZ) with 2-phenyl-4,6-bi(4-fluorophenyl)-1,3,5-triazine (BFPT) and 4,4′-dichlorodiphenyl sulfone (DCS). Model reactions monitored by HPLC indicated that BFPT had slightly higher reactivity than DCS in nucleophilic displacement reactions. The obtained random copolymers were characterized by FTIR, NMR, elemental analysis and GPC. The presence of sulfone and phthalazinone in the polymer chain results in an improvement in the solubility of poly(arylene ether phenyl-s-triazine)s in common organic solvents, such as N-methylpyrrolidone, N,N-dimethyl acetamide (DMAc), chloroform, sulfolane and pyridine. Thermal analysis reveal that the copolymers exhibit high glass transition temperatures (T_gs) ranging from 271–300 °C, and excellent thermal stability associated with decomposition temperatures for 5% mass-loss exceeding 503 °C. All copolymers are amorphous except PPESP28 as evidenced by WAXD. Their T_gs and solubility increase with an increase in sulfone content in the polymer backbone, while the crystallinity and overall thermal stability appear to decrease. This kind of phthalazinone-based copoly(arylene ether sulfone phenyl-s-triazine)s may be considered a good candidate for using as high-performance structural materials.     

Pendant crosslinked poly(aryl ether sulfone) copolymers sulfonated on backbone for proton exchange membranes

A series of sulfonated poly(aryl ether sulfone) copolymers containing phenyl pendant groups with sulfonic acid groups on the backbone were synthesized through condensation polymerization. The degree of sulfonation (DS) of the copolymers was controlled by changing the feed ratios of sulfonated to unsulfonated monomers. Post‐crosslink reactions are carried out with 4,4′‐thiodibenzoic acid (TDA) as a crosslinker and the carboxylic acid groups in TDA can undergo Friedel–Craft acylation with the phenyls pendent rings in sulfonated poly(arylene ether sulfone)s copolymers to prepare polymer electrolyte membranes for fuel cell applications. The chemical structures of crosslinked and uncrosslinked sulfonated poly(arylene ether sulfone)s copolymers (SPSFs and CSPSFs) were characterized by FTIR, ¹H NMR spectra. The thermal and mechanical properties of the membranes were characterized by thermogravimetric analysis and stress–strain test. The dependence of water uptake, methanol permeability, proton conductivity, and selectivity on DS was studied. Transmission electron microscopic observations revealed that SPSFs and CSPSFs membranes form well‐defined microphase separated structures. POLYM. ENG. SCI., 54:2013–2022, 2014. © 2013 Society of Plastics Engineers     

Synthesis and properties of poly(aryl ether ketone)s containing both biphenylene moieties and sulfone linkages in the main chain

Two monomers, 4,4′‐bis(4‐phenoxybenzoyl)biphenyl (BPOBBP) and 4,4′‐diphenoxydiphenyl sulfone (DPODPS), were conveniently synthesized via simple synthetic procedures from readily available materials. A series of novel poly(aryl ether ketone)s containing both biphenylene moieties and sulfone linkages in the main chain were synthesized by the modified electrophilic Friedel‐Crafts acylation copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBBP and DPODPS, over a wide range of BPOBBP/DPODPS molar ratios. The resulting polymers were characterized by Fourier transform infrared spectroscopy (FT‐IR), wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), etc. The results indicated that the copolymers with 30 to 35 mol% DPODPS were semicrystalline and had remarkably increased glass transition temperatures (T_gs) over the conventional poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) due to the incorporation of biphenylene units and sulfone linkages in the main chain. The copolymers with 30 to 35 mol% DPODPS had not only high T_gs of 176 to 177°C, but also moderate melting temperatures (T_ms) of 334 to 337°C, having good potential for the melt processing. The semicrystalline copolymers II to V had tensile strengths of 99.8 to 103.1 MPa, Young's moduli of 2.26 to 2.79 GPa, and elongations at break of 16.8 to 26.5% and exhibited outstanding thermal stability and good resistance to organic solvents. POLYM. ENG. SCI., 55:2140–2147, 2015. © 2015 Society of Plastics Engineers     

Synthesis and properties of poly(arylene ether)s based on 3‐pentadecyl 4,4'‐biphenol

A new biphenol, 3‐pentadecyl 4,4′‐biphenol, was synthesized starting from 3‐pentadecylphenol and was polycondensed with 4,4′‐difluorobenzophenone, 1,3‐bis(4‐fluorobenzoyl)benzene and bis(4‐fluorophenyl)sulfone to obtain poly(arylene ether)s with biphenylene linkages in the backbone and pendent pentadecyl chains. Inherent viscosities and number‐average molecular weights (M_n) of the poly(arylene ether)s were in the range 0.50 ? 0.81 dL g^?1 and 2.2 × 10⁴ ? 8.3 × 10⁴, respectively. Detailed NMR spectroscopic studies of the poly(arylene ether)s indicated the presence of constitutional isomerism which existed because of the non‐symmetrical structure of 3‐pentadecyl 4,4′‐biphenol. The poly(arylene ether)s readily dissolved in common organic solvents such as dichloromethane, chloroform and tetrahydrofuran and could be cast into tough, transparent and flexible films from their chloroform solutions. The poly(arylene ether)s exhibited T_g values in the range 35–60 °C which are lower than that of reference poly(arylene ether)s without pentadecyl chains. The 10% decomposition temperatures (T₁₀) of the poly(arylene ether)s were in the range 410–455 °C indicating their good thermal stability. A gas permeation study of poly(ether sulfone) containing pendent pentadecyl chains revealed a moderate increase in permeability for helium, hydrogen and oxygen. However, there was a large increase in permeability for carbon dioxide which could be attributed to the internal plasticization effect of pendent pentadecyl chains. © 2016 Society of Chemical Industry     

Synthesis and characterization of poly(ether sulfone) and poly(ether sulfone ketone) copolymers

Poly(ether sulfone) and poly(ether sulfone ketone) copolymers (I–V) were synthesized by the nucleophilic substitution reaction of 4,4′-dihydroxy diphenyl sulfone (DHDPS, A) with various mole proportions 4,4′-difluoro benzophenone (DFBP, B) and 4,4′-difluoro diphenyl sulfone (DFDPS, C) using sulfolane as solvent in the presence of anhydrous K₂CO₃. The polymers were characterized by physicochemical and spectroscopic techniques. All polymers were found to be amorphous, and the glass transition temperature (T_g) was found to increase with the sulfonyl content of the polymers. ¹³C-nuclear magnetic resonance (NMR) spectral data was interpreted in terms of the compositional triads, BAB, BAC, CAC, ABA, and ABB, and indicate that transetherification occurs at high concentration of DFBP units in the polymer (IV). The good agreement between the observed and calculated feed ratios validates the triad analysis. Thermal decomposition studies reveal that the thermal stability of the polymers increases with increase in the carbonyl content in the polymer. Activation energies for thermal decomposition were found to be in the range of 160–203 kJ mol⁻¹ with the cleavage of ϕ SO₂ bond being the preponderant mode of decomposition and depended on the block length of the sulfonyl unit. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2113–2121, 1999     

Processing induced morphological development in hydrated sulfonated poly(arylene ether sulfone) copolymer membranes

The development of morphological solid-state structures in sulfonated poly(arylene ether sulfone) copolymers (acid form) by hydrothermal treatment was investigated by water uptake, dynamic mechanical analysis (DMA), and tapping mode atomic force microscopy (TM-AFM). The water uptake and DMA studies suggested that the materials have three irreversible morphological regimes, whose intervals are controlled by copolymer composition and hydrothermal treatment temperature. Ambient temperature treatment of the membranes afforded a structure denoted as Regime1. When the copolymer membranes were exposed to a higher temperature, AFM revealed a morphology (Regime2) where the phase contrast and domain connectivity of the hydrophilic phase of the copolymers were greatly increased. A yet higher treatment temperature was defined which yielded a third regime, likely related to viscoelastic relaxations associated with the hydrated glass transition temperature (hydrated T_g). The required temperatures needed to produce transitions from Regime1 to Regime2 or Regime3 decreased with increasing degree of disulfonation. These temperatures correspond to the percolation and hydrogel temperatures, respectively. Poly(arylene ether sulfone) copolymer membranes with a 40% disulfonation in Regime2 under fully hydrated conditions showed similar proton conductivity (∼0.1 S/cm) to the well-known perfluorinated copolymer Nafion^® 1135 but exhibited higher modulus and water uptake. The proton conductivity and storage modulus are discussed in terms of each of the morphological regimes and compared with Nafion 1135. The results are of particular interest for either hydrogen or direct methanol fuel cells where conductivity and membrane permeability are critical issues.     

Poly(arylene ether nitrile) copolymers containing pendant phenyl: Synthesis and properties

A series of poly(arylene ether nitrile) copolymers (PENAPs) were synthesized with bisphenol A (BP-A), bisphenol AP (BP-AP) and 2,6-Dichlorobenzonitrile (DCBN) via a nucleophilic substitution polycondensation reaction. FTIR and ¹H-NMR were used to confirm the structure of PENAPs. Glass transition temperature (T_g) of PENAPs determined by differential scanning calorimetry (DSC) ranged from 154.2 to 200.8°C. The 5% weight lost temperature (T_5%) of PENAPs were 418.9–447.7°C. The tensile and DMA test indicated that PENAPs possessed excellent mechanical properties with tensile strength more than 92.8 MPa and storage modulus more than 1.0 GPa at about 150°C. The melt flowability was measured by rheology properties testing ranging from 80 to 1639 GPa at 290°C and under shear frequency 100 Hz, which indicated the copolymers had good flowability and thermal stability. Additionally, PENAPs could be dissolved in many solutions, which meant PENAPs had good solubility and can be processed by solution method.     

Poly(arylene sulfide sulfone) hybrid ultrafiltration membrane with TiO2‐g‐PAA nanoparticles: Preparation and antifouling performance

Poly(arylene sulfide sulfone) (PASS) is a kind of newly developed polymeric membrane material which has excellent mechanical strength, thermal stability, and solvent resistance. And, it would be a potential material for high temperature ultrafiltration and organic solvent filtration. In this article, PASS hybrid ultrafiltration membrane with improved antifouling property was prepared by mixing TiO₂ nanoparticles which were grafted with polyacrylic acid (PAA). These membranes were prepared by a phase inversion technique and their separation performance and antifouling property of the prepared membranes were investigated in detail by SEM, FTIR, EDS, contact angle goniometry, filtration experiments of water, and BSA solution. The results shown that the TiO₂‐g‐PAA nanoparticles dispersed well in membrane matrix, the hydrophilicity of the membranes prepared within TiO₂‐g‐PAA nanoparticles have been improved and these membranes exhibited excellent water flux and antifouling performance in separation than that of the pure PASS membranes and PASS membranes with TiO₂ nanoparticles. More specifically, among membrane sample M0, M1.5, and MP1.5, MP1.5 which contained 1.5 wt% TiO₂‐g‐PAA exhibited the highest water permeation (190.4 L/m² h at 100 kPa), flux recovery ratio, and the lowest BSA adsorption amount. POLYM. ENG. SCI., 55:2829–2837, 2015. © 2015 Society of Plastics Engineers     

Preparation and characterization of hyperbranched poly(ether sulfone) and its application as a coating additive for linear poly(ether sulfone)

Hyperbranched poly(ether sulfone) (HPES), a suitable coating additive for improving the rheological properties of linear poly(ether sulfone) (LPES), was easily produced via polymerization of commercially available bisphenol S (A₂ monomer, BPS) and synthesized 2,4′,6‐trifluoro‐phenylsulfone (BB′₂ monomer, TF). During this reaction, fluoro‐ or phenolic‐terminated HPES (F‐HPES or OH‐HPES) could be facilely obtained by controlling the feed mole ratios of the two monomers. The polymerization mode A₂ + BB′₂ was confirmed by analyzing the model compounds and the degree of branching (DB) was calculated systematically. In addition, the synthesized polymers' chemical structures were exhibited by FTIR, ¹H NMR as well as ¹⁹F NMR spectroscopy. Notably, the addition of 1 wt % HPES reduced the melt viscosity and improved the high temperature liquidity of LPES because of its unique spherical shape. Furthermore, the addition of HPES did not have a negative impact on the performance of LPES, which was attributed to the good miscibility between HPES and LPES. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43892.     

Multiblock poly(arylene ether nitrile) disulfonated poly(arylene ether sulfone) copolymers for proton exchange membranes: Part 1 synthesis and characterization

A series of multiblock copolymers based upon alternating segments of a hydrophilic disulfonated poly(arylene ether sulfone) and a hydrophobic fluorine-terminated poly(arylene ether benzonitrile) (6FPAEB) were synthesized and characterized for use as proton exchange membranes (PEM). The ion-exchange capacity of the block copolymers were varied by utilizing 4,4′-biphenol or hydroquinone in combination with 3,3′-disulfonated-4,4′-dichlorodiphenyl sulfone (SDCDPS) to form the hydrophilic segments. The alternating block copolymer morphology was achieved by using mild temperatures to link the oligomers together and minimize ether–ether interchange reactions. Both the 4,4′-biphenol and hydroquinone based membranes showed high proton conductivity with moderate water uptake and good mechanical properties. The block copolymers displayed nanophase separated morphologies, confirmed by transmission electron microscopy (TEM) and small angle x-ray scattering (SAXS). The strong membrane performance was attributed to the multi-phase morphology.     

Effect of sulfonation degree on molecular weight,thermal stability,and proton conductivity of poly(arylene ether sulfone)s membrane

Direct copolymerization of sulfonated and non-sulfonated difluorodiphenyl sulfones as dihalide monomers with hydroquinone and also 4,4′-(4,4′-sulfonylbis-(1,4-phenylene)bis(oxy)) diphenol as diols led to preparation of two series of poly(arylene ether sulfone)s. Copolymers with different degrees of sulfonation (40, 50 and 60%) were synthesized in order to evaluate their potential for fuel cell application. ¹H-NMR, FT-IR, and mass spectroscopy were used for characterization of prepared monomers and copolymers. Differential scanning calorimetry and thermogravimetric analysis were applied for investigation and comparison of the thermal properties of copolymers. Laser light scattering (LLS) was employed to calculate zeta potential, conductivity, and molecular weight of copolymers. Copolymers were obtained in high and sufficient molecular weight that was basic need to reach reasonable physical and thermal properties for applications as fuel cell membrane. The effect of similar structural repeating units with different sizes on the final properties of sulfonated poly(ether sulfone)s was investigated to compare their potential in fuel cell membrane.     

Synthesis and properties of poly(ether nitrile sulfone) copolymers with pendant methyl groups

Poly(ether nitrile) and poly(ether nitrile sulfone) copolymers with pendant methyl groups were prepared by the nucleophilic substitution reaction of 2,6′‐dichlorobenzonitrile with methyl hydroquinone and with varying mole proportions of methyl hydroquinone and 4,4′‐dihydroxydiphenylsulfone using N‐methyl pyrrolidone as a solvent in the presence of anhydrous K₂CO₃. The polymers were characterized by different physicochemical techniques. Copolymer composition was determined using the FTIR technique. Thermogravimetric data revealed that all polymers were stable up to 420°C with a char yield above 40% at 900°C in a nitrogen atmosphere. The glass‐transition temperature increased and the activation energy and inherent viscosities decreased with an increase in the concentration of the 4,4′‐dihydroxydiphenylsulfone units in the polymer. Trimerization reactions were favorable with an increase in the concentration of methyl hydroquinone units in the polymer. The crystallinity of the polymer was also studied using wide‐angle X‐ray diffraction. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1987–1994, 2005     

新型聚芳醚砜共聚物的制备及其性能

以4,4’-二氯二苯砜、4,4’-二羟基二苯砜和2,4-二羟基二苯砜为单体,通过缩聚合成一系列主链含异构体醚键单元的聚芳醚砜共聚物,利用核磁共振碳谱(13C NMR)、差示扫描量热分析(DSC)和高压毛细管流变仪对产物进行了测试和分析。对比不同产物的熔体黏度、玻璃化转变温度和力学性能,发现随着共聚单元含量的增加,聚芳醚砜共聚物的流动性逐渐提高,玻璃化转变温度逐渐降低,并且屈服点伸长率和缺口冲击强度均逐渐提高。这一结果对实际应用中提高聚芳醚砜树脂流动性和韧性、降低热加工温度等具有重要的指导意义。     

Synthesis of poly(arylene benzimidazole) sulfone (PABIS) and preparation of hollow PABIS microspheres

4,4'‐Di(benzimidazolyl)benzene sulfone, as the monomer, is very readily available by the reaction of 4,4'‐dicarboxydiphenyl sulfone with o‐phenylenediamine, and poly(arylene benzimidazole) sulfone (PABIS) has been synthesized by the condensation polymerization of bis(4‐fluorophenyl) sulfone with di(benzimidazolyl)benzene sulfone via an N–C coupling reaction. The structure of the polymer was characterized by Fourier transform IR spectroscopy, ¹H NMR spectroscopy and elemental analysis, and the results showed agreement with the proposed structure. DSC and thermogravimetric measurements showed that PABIS possesses a high glass transition temperature (T_g = 321 °C) and good thermal stability with high decomposition temperature (T_d > 530 °C). Additionally, PABIS exhibits good solubility in most polar organic solvents. Based on the good chemical and physical properties, hollow PABIS microspheres with diameters in the range 0.3–1.8 mm were prepared by the micro‐liquid technique and the double‐layer latex technique. A new double T‐channel droplet generator was developed for continuous fabrication of controlled‐size hollow PABIS microspheres. The structures of the hollow PABIS microspheres were characterized, and they possessed equal wall thickness and good spherical symmetry. © 2013 Society of Chemical Industry     

Synthesis and properties of poly(aryl ether sulfone ether ketone ketone) (PESEKK)

4,4′‐bis(Phenoxy)diphenyl sulfone (DPODPS) was synthesized by reaction of phenol with bis(4‐chlorophenyl) sulfone in tetramethylene sulfone in the presence of NaOH. Two poly(aryl ether sulfone ether ketone ketone)s (PESKKs) with high molecular weight were prepared by low temperature solution polycondensation of DPODPS and terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC), respectively, in 1,2‐dichloroethane and in the presence of aluminum chloride (AlCl₃) and N‐methylpyrrolidone (NMP). The resulting polymers were characterized by various analytical techniques, such as FT‐IR, ¹H‐NMR, DSC, TG, and WAXD. The results show that the T_g and T_d of PESEKKs are much higher, but its T_m is lower than those of PEKK. The other results indicate that PESEKKs exhibit excellent thermostabilities at 300 ± 10°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 489–493, 2005     

Sulfonated poly(ether ether sulfone) copolymers for proton exchange membrane fuel cells

Novel aromatic sulfonated poly(ether ether sulfone)s (SPEESs) with tert‐butyl groups were synthesized by aromatic nucleophilic polycondensation of disodium 3,3′‐disulfonate‐4,4′‐dichlorodiphenylsulfone (SDCDPS), 4,4′‐dichlorodiphenylsulfone (DCDPS), and tert‐butylhydroquinone (TBHQ). The resulting copolymers showed very good thermal stability and could be cast into tough membranes. The morphology of the membranes was investigated with atomic force microscopy. The proton conductivity of SPEES‐40 membranes increased from 0.062 S/cm at 25°C to 0.083 S/cm at 80°C, which was higher than the 0.077 S/cm of Nafion 117 under the same testing conditions. These copolymers are good candidates to be new polymeric electrolyte materials for proton exchange membrane fuel cells. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1443–1450, 2007     

Synthesis and characterization of novel copolymers of poly(ether ketone ketone) and poly(ether ketone sulfone imide)

A new monomer containing sulfone and imide linkages, bis{4-[4-(p-phenoxyphenylsulfonylphenoxy)benzoyl]-1,2-benzenedioyl}-N,N,N′,N′-4,4′-diaminodiphenyl ether (BPSPBDADPE), was prepared by the Friedel–Crafts reaction of bis(4-chloroformyl-1,2-benzenedioyl)-N,N,N′,N′-4,4′-diaminodiphenyl ether with 4,4′-diphenoxydiphenyl sulfone. Novel copolymers of poly(ether ketone ketone) and poly(ether ketone sulfone imide) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of terephthaloyl chloride with a mixture of DPE and BPSPBDADPE. The polymers were characterized by different physico-chemical techniques. The polymers with 10–25?mol% BPSPBDADPE are semicrystalline and had increased T _gs over commercially available PEEK and PEKK (70/30) due to the incorporation of sulfone and imide linkages in the main chains. The polymer IV with 25?mol% BPSPBDADPE had not only high T _g of 194?°C but also moderate T _m of 338?°C, having good potential for melt processing and exhibited high thermal stability and good resistance to common organic solvents.     

Viscometric behavior of disulfonated poly(arylene ether sulfone) random copolymers used as proton exchange membranes

tert-Butylphenyl-terminated disulfonated poly(arylene ether sulfone) random copolymers with a sulfonation degree of 35 mol% (BPS35) and controlled molecular weights (M_n), 20-50 kg mol⁻¹, were successfully prepared by direct copolymerization of the two activated halides, 4,4′-dichlorodiphenyl sulfone (DCDPS) and 3,3′-disulfonate-4,4′-dichlorodiphenyl sulfone (SDCDPS) with 4,4′-biphenol and the endcapper, 4-tert-butylphenol. Dilute viscosity measurements of the BPS35 random copolymers were successfully conducted in NMP containing various concentrations of LiBr from 0.01 to 0.2 M and mostly at 0.05 M according to the measured theory. The effects of salt concentration and molecular weights of the copolymers on the viscometric behavior were studied and compared with published data for sulfonated polystyrene. The charge density parameter (ξ) for the BPS35 copolymers was determined to be smaller than 1, suggesting that no counterion condensation occurs. Studies of the effect of ionic strength (I) on the intrinsic viscosities ([η]) under theta condition were obtained by plotting [η] vs. I^−1/2 and extrapolating to infinite ionic strength. For salt-free BPS35 solutions, the viscometric behavior was shown to fit well with the Liberti-Stivala equation, providing a way to determining intrinsic viscosity when the copolymer charge is fully screened. Intrinsic viscosity and molecular weight characterization of BPS35 copolymers by SEC and static light scattering are also presented. The results are very useful for characterizing polymeric electrolyte membrane (PEM) for fuel cells, reverse osmosis and ionic transducer membranes.