New poly(carbobetaine)s made from zwitterionic diallylammonium monomers

A series of new hydrolytically stable poly(carbobetaine)s with varying dist ance between the ammonium and the carboxylate group was synthesized, exclud ing the presence of residual salt in the polymers, together with cationic a nd sulfobetaine analogues. The poly(carbobetaine)s show improved solubility compared to analogous poly(sulfobetaine)s, and are more hygroscopic. Their thermal stability depends strongly on the length of the spacer group separ ating the ammonium and the carboxylate group. The poly(carbobetaine)s are t ypically amorphous, but for long spacer groups, they exhibit a superstructu re. They are capable of forming homogeneous blends with a number of inorgan ic salts, following the selectivity of the Hofmeister series, thus giving a ccess to new organic-inorganic hybrid materials.