Synthesis and characterization of sulfonated telechelic bisphenol A polycarbonate ionomers

Bisphenol A polycarbonate telechelic sulfonated ionomers have been prepared by melt polycondensation using bis(methyl salicyl) carbonate (BMSC), bisphenol A (BPA) and the sodium salt of sulfobenzoic acid phenylester (SBENa). Using an activated carbonate such as BMSC it is possible to decrease both reaction temperature and time respect to a standard polycondensation that use diphenylcarbonate (DPC) as carbonate precursor. Using the activated carbonate, ionomers with low Fries by-products and with good color have been obtained. The addition of SBENa permits the preparation of telechelic ionomers with ionic contents up to 3 mol%. All the properties of the telechelic ionomer obtained using BMSC are superior respect to those of the telechelic ionomers obtained using DPC. In particular, the ionomers prepared using BMSC are stable up to 400 °C and present higher glass transition temperature and storage modulus respect to standard PC.