new and improved polyamino acid polymers and derivatized polyamino acid polymers are provided . relatively high molecular weight poly are prepared by solid phase polymerization of aspartic acid or glutamic acid in the presence of a super phosphoric acid catalyst . the poly may be hydrolyzed to provide biodegradable polyaspartic acid or polyglutamic acid homopolymer having weight average molecular weights ≧ 70 , 000 . higher molecular weight , water soluble , cross - liked polyamino acid polymers and gels are also provided . in a preferred embodiment , the poly are derivatized in aqueous media to provide storage stable , substantially linear , biodegradable polyamino acid polymers having pendant hydroxyl , ether , hydroxyalkylaminoalkyl , hydroxyalkoxyalkyl , carboxyl , sulfonoalkyl and / or phosphonoalkyl functionalities . the polymers are useful as chelants in various water treatment applications .