Synthesis And Properties Of Multiblock Copolymer Ionomers Containing Phthalazinone Ether Ketone And Fluorene Ether Ketone Moieties

2 - (4 - chloro-benzoyl) benzoic acid was synthesized by Friedel-Crafts reaction. Bisphenol A-phthalazinone monomer was synthesized from nucleophilic substitution reaction and the C-N coupling reaction. Sulfonic acid has a strong proton conductivity. High-performance material with phthalazinone ether ketone skeleton has excellent mechanical properties, chemical and electrochemical stability, low permeability of Alcohol. High-performance materials with fluorene structure with good moisture retention under the higher temperture. To combine these effectiveness, two series of sulfonated multiblock copoly(ether-ketone)s containing phthalazinone ether ketone and ?uorene ether ketone moieties have been designed and synthesized successfully by two-step polycondensation.The water uptakes of the copolymers with varying sized sulfonated poly(phthalazinone ether ketone) block as hydrophilic blocks are moderate. In this series polymers 10a-10e gave the proton conductivities varying from 1.38×10-4 to 6.23×10-3 S/cm. The water uptakes of the copolymers with varying sized sulfonated poly(fluorene ether ketone) blocks as hydrophilic blocks are high than 300%. These copolymers showed better proton conductivity. The copolymers with sulfonated poly(phthalazinone ether ketone) blocks had strong alcohol resistance at refluxing temperature. Whilst the copolymers containing sulfonated poly(fluorene ether ketone) hydrophilic blocks were dissolved in methanol and ethanol. The cast films of the title ionomers were transparent, ductile, and flexible. Moreover, these copolymers demonstrated greatly improved oxidative and thermal stabilities.Transmission electron microscopy (TEM) photographs revealed that significant hydrophilic/hydrophobic micro-phase separation occurs in the membranes and a better phase separation happened in the membrane fabricated with two pot method of two step polycondensation. Especially, the proton conductivity of the copolymers with sulfonated phthalazinone ether ketone blocks was close that of Nafion. The copolymers comprising sulfonated poly(phthalazinone ether ketone) hydrophilic blocks and poly(?uorene ether ketone) hydrophobic blocks is a promising proton exchange membrane material for proton exchange membrane fuel cell used methanol or ethanol as fuel.