Sulfonated poly (ether-block-ester) ionomers with anions in the polyester hard segments

A series of poly(ether-block-ester) ionomers with different content of sodi um sulfonate groups in the hard segments, and the random copolyesters poly( butylene terephtalate)/butylene isophthalate (PBT/BI) and poly(butylene ter ephalate/butylene 5'-sulfoisophthalate sodium salt (PBT/SBI) have been synt hesized and examined. The methods of dynamic mechanical thermal analysis an d differential scanning calorimetry were used to determine the effect of io nic units on the physical properties of sulfonated poly(ether-block-ester) (SPEE) ionomers and PBT/BI, PBT/SBI copolymers. It was established that the melting temperature and crystallization temperature of the SPEE ionomers d ecreases with the increase of content sodium 5-sulfoisophthalate in the har d segments, and that the crystallinity gradually decreases with the increas e of ionic units content. The effect of ionic units content in hard segment s on glass transition temperature of both soft and hard phase, E', E" and t an delta were studied. Copyright (C) 1999 John Wiley & Sons, Ltd.