The preparation and characterization of new polymeric ionomers based on a fully aromatic poly(arylene ether) backbone with locally pentasulfonated pendent groups for applications as proton exchange membranes is reported. The high molecular weight sulfonated polymers were obtained by the polycondensation of new (2,6-difluorophenyl) (4-(1,2,3,4,5-pentaphenylbenzene)phenyl)methanone, 4,4 0 -difluorodiphenyl methanone, and 4,4 0 -dihydroxydiphenylsulfone, followed by sulfonation using sulfuric acid in high yields. The polymers produced tough, flexible, and transparent membranes by solvent casting. Membranes with ion exchange capacities between 0.8 and 1.7 mEq g -1 showed high proton conductivities and low methanol permeabilities. Compared to Nafion 117, these sulfonated membranes exhibited better microphase separation morphologies. The fully humidified membranes also exhibited considerably good mechanical properties, with tensile strengths from 35 to 45 MPa and elongations at break from 23 to 49%. This investigation demonstrates a controllable high density sulfonated side group of a poly(arylene ether sulfone) membrane with tunable and balanced properties, which is promising for proton exchange membrane fuel cell technology.

Novel side‐chain‐type sulfonated poly(arylene ether) with pendant sulfoalkyl group copolymers (PSA‐SPAE‐6F) have been synthesized by direct copolymerization from a new sulfonated monomer, sodium 3‐(4‐(2,6‐difluorobenzoyl)phenyl)propane‐1‐sulfonate. The sulfonate content could be easily controlled by adjusting the sulfonated and the unsulfonated monomer feed ratio. The obtained copolymers all show good thermal and mechanical properties. It should be noted that the most highly sulfonated copolymer, PSA‐SPAE‐6F90 with an ion exchange capacity of 1.30 mequiv · g−1, shows a proton conductivity of 0.11 S · cm−1 and a water swelling ratio of only 12.9% at 100 °C, which indicates its high proton conductivity and excellent dimensional stability in hot water.magnified image

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An improvement in the processability of poly(ether ether ketone) (PEEK) and PEEK/carbon fiber (PEEK/ CF) composites with less influence on the other properties is important. A novel high temperature lubricant, GENIO-PLAST PELLETS (GPPS), was used to decrease the melt viscosity of PEEK and PEEK/CF composites. PEEK/ GPPS and PEEK/CF/GPPS compounds were characterized by dynamic rheometry, universal tester, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results showed that a small amount of GPPS could decrease the melt viscosity of the compounds during processing, and improve the dispersion uniformity of the carbon fiber in the PEEK matrix, and further enhance the tensile strength of PEEK/CF composites, but have little effect the thermal stability of the compounds.