Mechanical and Thermal Properties of Polylactic Acid/Polyketone Polymer Blends

Abstract

This study investigates the mechanical and thermal properties of polylactic acid (PLA) blended with polyketone (PK) at various weight ratios (100/0, 90/10, 80/20, 70/30, and 60/40) without the use of a compatibilizer. The blends were prepared via twin-screw extrusion followed by injection molding. Results showed that adding PK slightly improved the impact strength, reaching a maximum of 25.14 J/m at the 60/40 ratio. However, tensile strength, Young’s modulus, and elongation at break are decrease with increasing PK content. Scanning electron microscopy (SEM) confirmed phase separation and non-uniform PK dispersion within the PLA matrix, which correlated with the reduction in mechanical performance. Thermal analysis using DSC and Vicat softening temperature (VST) testing indicated an increase in (Tcc) and VST with higher PK content. The maximum VST observed was 61.70 °C at the 60/40 blend ratio. These findings suggest that although PLA and PK have limited compatibility, blending PK into PLA can improve properties such as impact resistance and thermal.