PHYSICAL-PROPERTIES OF POLY(BETA-HYDROXYBUTYRATE) POLY(EPSILON-CAPROLACTONE) BLENDS

Compression-moulded sheets of bacterially produced poly(beta-hydroxybu tyrate) (PHB) blended with synthetic poly(epsilon-caprolactone) (PCL) were investigated over the complete composition range from pure PHB to pure PCL. These blends are of potential interest because both compone nts are biodegradable. Although PHB and PCL are immiscible, they forme d mechanicaly compatible films containing phase-separated partially cr ystalline domains. The mechanical properties varied considerably with composition. The low melting point of PCL (approximately 60-degrees-C) prevented temperature-resistant blends from being obtained for compos itions containing less than 60% PHB.