PREPARATION AND PROPERTIES OF A-B-A TRI-BLOCK COPOLYMER MEMBRANES CONSISTING OF N-HYDROXYALKYL L-GLUTAMINE AS THE A-COMPONENT AND L-ALANINE AS THE B-COMPONENT

A-B-A type tri-block copolymer consisting of N-hydroxyalkyl L-glutamine as the A component and L-alanine as the B component as well as the corresponding random copolymers and homopolymers were prepared by aminoalcoholysis with 2-amino-1-ethanol, 3-amino-1-propanol, or 5-amino-1-pentanol, and crosslinking with octamethylenediamine on the starting polymer membranes including gamma -benzyl-L-glutamate residue. The relation between their bulk structure and membrane properties was investigated. Biodegradation of samples in vitro by protease indicated that the degradation was a bulk rather than a surface phenomenon.