PREPARATION AND POLYMERIZATION OF N-CARBO XYANHYDRIDES OF ALPHA-AMINO-ACIDS

N-Carboxyanhydrides (NCA) belong to interesting derivatives of alpha-a minoacids. They polymerize to synthetic poly(aminoacids) which are imp ortant enzymatically degradable polymers. The main methods ed NCA prep aration, characterization of NCA and their reactions with nucleophiles are described. The mechanisms of polymerization reactions are discuss ed as well as their possible affecting by the choice of reaction condi tions and initiation mechanism. The polymerization course correspondin g to so called ''living polymerization'', which gives defined polymers suitable for biomedical applications purposes, can be attained by the proper choice of reaction conditions.