The effect of blending and the addition of small amounts of TiO2 nanoparticles on the dynamic
mechanical properties of PLA/PHBV, PLA/PCL and PHBV/PCL blends is reported in this paper. The
storage modulus of the PLA/PHBV blends was higher than those of both PLA and PHBV in the
temperature region below the glass transition of PHBV, but the PLA/PCL and PHBV/PCL bends did not
show a similar feature. The E0 values between the glass transitions of PLA and PHBV depended on the
blend compositions and morphologies. The presence of titania nanoparticles had little effect on the E0
values of all the investigated blends. The cold crystallization transition of PLA shifted to lower
temperatures in the PLA/PHBV blends, and shifts in the Tgs of the two polymers indicated partial
miscibility at the polymer-polymer interfaces. This partial miscibility reduced the chain mobilities of
these polymers, which could be seen in a reduction in the damping during their respective glass
transitions. Blending and nanoparticle addition had little influence on the glass transition temperatures
of PLA and PCL in the PLA/PCL blends, but the glass transitions of PHBV and PCL in the PHBV/PCL blends
were respectively at higher and lower temperatures than those of the neat polymers, which is a
somewhat abnormal observation. The PCL glass transition peaks became broader as a result of blending,
which was attributed to the incompatibility of the polymers in the blends, because blending had no
influence on the PCL crystallinity.