Physical and biodegradation properties of A–B–A type block copolymer membranes consisting of poly( N-hydroxypropyl- l-glutamine) as the A component and polybutadiene as the B component

Abstract

A–B–A type block copolymer, PHPG–PB–PHPG, membranes consisting of poly( N-hydroxypropyl-L-glutamine) (PHPG) as the A component and polybutadiene (PB) as the B component were prepared by performing aminolysis reaction with 3-amino-1-propanol together with a cross linking reaction with 1,8-octamethylenediamine (OMDA) on membranes of the starting block copolymer, PMLG–PB–PMLG, that consisted of poly(γ-methyl-L-glutamate) (PMLG) and PB. The relationship between their bulk structure and properties was evaluated with regard to the swelling ratio in water ( q), the rate of water vapor permeability ( V f ), tensile properties, and enzymatic degradation behavior in a pseudo-extracellular fluid (PECF). The tensile property of the hydrophilic membranes was highly dependent on q in PECF, and on the hydrophobic portions in molecular chains, whose behavior was typical of an elastomer. Biodegradation of the membranes in vitro by bromelain indicated that the degradation took place in bulk rather than on the surface, and that the rate of degradation was also highly dependent on q in the samples as well as on the hydrophobic portion of the membranes in PECF.