ACID-CATALYZED COPOLYMERIZATION OF ASPARTIC-ACID WITH OMEGA-AMINO ACID - BIODEGRADABILITY AND CA2-OMEGA-AMINO ACID)( CHELATING ABILITY OF POLY(ASPARTIC ACID CO)

The polycondensation of L-aspartic acid (1) with various omega-amino a cids (2) using phosphoric acid catalyst produced poly(succinimide-co-o mega-amino acid)s (3), which was followed by alkali hydrolysis to poly (aspartic acid-co-omega-amino acid) (4). The Ca2+ chelating abilities of 4 depended on the content of comonomer unit in the copolymer and on the kind of amino acids. For the copolymer using 11-aminoundecanoic a cid (2d) as a comonomer, the Ca2+ chelating ability was higher than th at of poly(sodium acrylate). For poly(aspartic acid-co-6-aminocaproic acid) (4c), there was a tendency to increase according to the increase of 6-aminocaproic acid (2c) unit in the copolymer. The biodegradabili ty of the copolymer in the case of 2c as a comonomer, evaluated by TOC measurement, was 63 %, which was the highest degradability among the copolymers having different methylen length. The biodegradability of 4 c decreased with increasing the 2c unit in 4c.