Assessment of localization and degradation of ZnO nano-particles in the PLA/PCL biocompatible blend through a comprehensive rheological characterization

The aim of this work was to investigate the effect of addition of various amounts of zinc oxide (ZnO) nanoparticles on the polylactide/polycaprolactone (PLA/PCL) blend prepared by melt mixing method. The morphological, rheological and degradation of prepared nanocomposites were studied. The morphology was characterized as dispersed PCL droplets into the PLA matrix, and according to Young's equation, zinc oxide nanoparticles (ZnO-NPs) was anticipated to preferentially locate in the matrix phase. The results of ATR-FTIR and the hydrolytic degradation tests demonstrated that, addition of ZnO-NPs introduced an accelerated degradation on the PLA/PCL blends. Subsequently, comprehensive linear viscoelastic evaluations were carried out to support these results and also give a deeper insight on the possible influences associated with the ZnO-NPs incorporation. Rheological results showed that with increasing nanoparticles, the elastic modulus and the complex viscosity decreased, which it was correlated to the degradation and chain scission of polymeric chains induced by ZnO-NPs. (C) 2018 Elsevier Ltd. All rights reserved.