The results of the rheological properties are shown in Figure . The rheological measurements of the PLA and PCL matrices confirmed the typical melt behaviour of uncrosslinked polymers . Both matrices exhibited zero-shear viscosity (Figure , 6b) -a constant plateau at a value of ~ 9500 Pas and ~ 2000 Pas for PCL and PLA, respectively. The addition of µHAp and nHAp affected the viscoelastic properties of composites with typical behaviour of filled polymer melts .