Preparation and properties of A-B-A type block copolymer membranes consisting of poly(N-hydroxypropyl-L-glutamine) as the A component and polyisoprene as the B component.

A-B-A type block copolymer (GIG(P)) membranes consisting of poly(N-hydroxypropyl-L-glutamine) (PHPG) as the A component and polyisoprene (PI) as the B component were prepared by carrying out aminoalcoholysis reaction with 3'-amino-1-propanol and a crosslinking reaction with 1,8-octamethylenediamine (OMDA) on membranes of the starting block copolymer (GIG) membranes consisting of poly(gamma-benzyl L-glutamate) (PBLG) and PI. It was shown that the effective crosslink density was proportional to the molar % of OMDA in the reaction mixture. The relation between their bulk structure and membrane properties was investigated, such as the swelling ratio q in a pseudo-extracellular fluid (PECF), tensile properties, and enzymatic degradation behaviour of the membranes in PECF. The tensile properties of the hydrophilic membranes were highly dependent on q in PECF, and on the hydrophobic portions in molecular chains, whose behaviour was typical of an elastomer. Biodegradation of samples in vitro by papain indicated that the rate of degradation was also highly dependent on q of membranes in PECF.