Disclosing the role of surface and bulk erosion on the viscoelastic behavior of biodegradable poly(epsilon-caprolactone)/poly(lactic acid)/hydroxyapatite nanocomposites

摘要

In this study, biodegradable polymer blends and their nanocomposites were prepared using poly(epsilon-caprolactone) (PCL) and poly(lactic acid) (PLA) as blending components and hydroxyapatite (HA) nanoparticles as reinforcement. X-ray diffraction spectra showed that the presence of HA nanoparticles enhanced the intensity of the peaks (100) and (200) corresponding to the PCL's crystalline planes. The transmission electron microscopy images confirmed the high tendency of HA nanoparticles to locate in the PLA phase. The water uptake values of samples measured at pH 4 were more than those measured at other pH values. The weight loss behavior of blends in acidic medium was completely different from that in basic and neutral media. The Williams-Landel-Ferry equation and time-temperature superposition principle were applied to the creep compliance of the samples and their master curves were determined at reference temperature of 30 degrees C, and the mechanical properties of samples were predicted in other conditions. The effect of pH on the creep-recovery response of studied samples was analyzed. From this analysis, it could be found that at pH 4, the creep stain increased, while, at pH 7, there was no a significant change in the viscoelastic property. (c) 2018 Wiley Periodicals, Inc.