Morphology, interfacial and mechanical properties of polylactide/poly(ethylene terephthalate glycol) blends compatibilized by polylactide-g-maleic anhydride

Polylactide/poly(ethylene terephthalate glycol) (PLA/PETG 80/20 wt) blends compatibilized with polylactide-g-maleic anhydride (PLA-g-MAH) were prepared by melt blending and the rheological, morphological and mechanical properties of the blends were studied. PLA/PETG (80/20 wt) blend formed a typical sea-island morphology, while upon compatibilization, the size and size distribution of the dispersed phase decreased significantly and the 3 wt% PLA-g-MAH compatibilized blend exhibited the smallest phase size and the narrowest distribution of the dispersed particles. The interfacial tension between PLA and PETG was determined from the morphological characteristics and the viscoelastic response of PLA/PETG blends via using two emulsion models. A minimum for PLA/PETG blend containing 3 wt% PLA-g-MAH was observed from both Palierne model and G-M model. The elongation-at-break increased by similar to 320%, from 6.9% for PLA to 28.7% for the blend containing 3 wt% PLA-g-MAH without significant loss in the tensile modulus and tensile strength. (C) 2014 Elsevier Ltd. All rights reserved.