Dynamic Rheology of Poly(3-hydroxybutyrate-co-4-Hydroxybutyrate) /Clay Biocomposites

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) P(3HB-co-4HB)] composites filled with clay were prepared by a melt blending process. Dynamic rheology of the composites was measured by means of a rotational rheometer. The results showed that the interlayer spacing of the clay increased owing to the presence of the P(3HB-co-4HB) melt in the interlayer regions of the clay. The storage and the loss moduli of the composite samples increased with the increasing frequency, and decreased with the increasing temperature. The addition of the clay enhanced the oscillatory thinning behavior of the composite melts, and improved the processability of the P(3HB-co-4HB) melt. The decrease of the viscosity by increasing both frequency and temperature was feasible and effective for the composites with the clay contents of 1 and 2 wt.%.