Effect of electron irradiation on the properties of poly(3-hydroxybutyric acid) fibres and their in vitro degradation

Abstract The effect of electron irradiation on chemical and mechanical properties and the in vitro behaviour of poly(3-hydroxybutyric acid) (PHB) fibres was investigated by gel permeation chromatography (GPC), solution viscosity, and tensile tests. The number-average ( M N ), weight-average ( M W ), Z-average ( M Z ), and viscosity-average ( M V ) molar masses of PHB in the basic, in vitro stored, and irradiated fibres were determined. Upon the electron irradiation, the number of bond cleavages per molecule varied with the dose of irradiation, the weight-average molar mass decreased by 43% and the tenacity by 23%. The hydrolytic degradation of irradiated PHB fibres in vitro was only about 10% higher than for untreated PHB fibres.