Influence of Polyethylene Glycol on the Morphology and Mechanical Properties of the Eco-Friendly Blends of Polylactic Acid

Document Type : Regular Article

Authors

School of Chemical, Petroleum and Gas Engineering Iran University of Science and Technology, Tehran, Iran

Abstract
The goal of this study was to examine the morphology and characteristics of a blend of polylactic acid (PLA) with thermoplastic corn starch (TPS) and polyethylene glycol (PEG-400) using the extrusion process. The blends were evaluated through the tensile and impact strength tests, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The experimental design method was selected to quantitatively analyze the influence of the content of TPS and concentration of the plasticizer on mechanical properties. Results from the tensile test showed that the addition of PEG-400 decreased tensile strength and elastic modulus, but increased elongation at break and impact strength, significantly. The blend with 20% TPS and 20 phr PEG-400 had the best overall performance in terms of tensile strength, elastic modulus, elongation at break, and impact strength. The SEM analysis indicated increased incompatibility and phase separation in samples with 40% TPS. Additionally, at high concentrations of PEG-400, the excessive plasticizer caused polymer saturation, resulting in unabsorbed plasticizer and phase separation. The findings suggest that the blend with 20% TPS and 20 phr PEG-400 could be suitable for use in eco-friendly applications.

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