Influence of Reactive Melt Mixing on Mechanical Behavior of Chain Extended PLLA/Thermoplastic Polyurethane Blends

摘要

Control of thermal degradation and melt strength of Poly (lactic acid), PLA, during melt processing while improving the toughness of the obtained samples is still a challenge for the polymer industry. Poly (L-lactide acide) (PLLA)/Thermoplastic polyurethane (TPU) blends were prepared in compositions of 70/30% and 50/50% in presence of multifunctional epoxy chain extender. A laboratory internal mixer was used to prepare the samples via reactive melt mixing. The effect of TPU on tensile modulus and elongation at break of chain extended PLLA were investigated. The tensile properties of the obtained samples show significant improvement in ductility of the PLA/TPU blends whereas chain extender contributed positive effect on the elastic modulus and strain at break of prepared blends. SEM micrographs of the samples show improved adhesion at the interface for samples incorporating multifunctional chain extender.