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.