Production of PLA/NR blends compatibilized with EE-g-GMA and POE-g-GMA: an investigation of mechanical, thermal, thermomechanical properties and morphology

Poly(lactic acid) (PLA)/natural rubber (NR) blends were compatibilized with elastomeric ethylene grafted with glycidyl methacrylate (EE-g-GMA), and poly(ethylene octene) grafted with glycidyl methacrylate(POE-g-GMA), aiming at the PLA toughening. The blends were processed using a twin-screw extruder and then injection molded. The mechanical, thermal, and thermomechanical properties and morphology were investigated. The addition of 10% NR to PLA resulted in a 77% increase in impact strength. Incorporating 10% of EE-g-GMA and POE-g-GMA in the blends promoted a significant increase in impact strength, with gains of 256% and 250%, respectively. Elastic modulus and tensile strength decreased and the elongation at break compared increased to pure PLA. Therefore, the developed blends exhibited ductile behavior. The heat deflection temperature showed no significant differences between the blends and pure PLA, indicating that the thermomechanical stability was maintained. The differential scanning calorimetry analysis confirmed an increase in the degree of crystallinity. Additionally, the incorporation of EE-g-GMA accelerated the blend’s crystallization. The thermal stability of the compatibilized blends was higher than PLA, confirming the increased tendency of the degree of crystallinity. The morphology indicated a refinement, good dispersion, and adhesion of the NR phases in the PLA matrix, contributing to improving toughness. These results show that the blends have the potential to produce eco-friendly materials, contributing to a more environmentally friendly cycle.