Mechanical and Thermal Behavior of PLA/PEgAA Blends

摘要

The aim of this work was to evaluate the effect different polyethylene grafted with acrylic acid (PEgAA) copolymer content on the mechanical and thermal properties and morphology of poly(lactic acid) (PLA) biopolymer. The PLA/PEgAA blends containing 5, 10, 15 and 20% (wt) of PEgAA copolymer were prepared by extrusion followed by injection molding and characterized by Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA),mechanical properties and Scanning ElectronMicroscopy (SEM). FTIR analysis indicated that a polyesterification reaction between the hydroxyl groups of PLA and the carboxyl groups of PEgAA may have occurred. DSC and DMTA analyzes indicated that the addition of PEgAA to PLA lead to the decrease in cold crystallization (T_(cc)) temperature of PLA. The impact strength of PLA was increased with the increase in the PEgAA content up to 15%. The PEgAA domains size increased with the increase in the PEgAA content, indicating a weak interaction between the PLA and PEgAA phases.