Physical, mechanical and thermal properties of PLA/ABS/PP/PS polymer blend composites

Purpose This work attempts to produce innovative ternary and quaternary polymer blends of polylactic acid (PLA) with acrylonitrile–butadiene–styrene (ABS), polypropylene (PP) and polystyrene (PS) to improve the thermal and mechanical properties of PLA-based biodegradable composites for applications in industry. Design/methodology/approach In this present research study, blends of PLA, ABS, PP and PS were synthesized in various weight fractions through high-torque twin-screw extrusion with the aim of obtaining homogeneous phase dispersion. The resulting extrudates were then compression molded to obtain specimens of standard dimensions for testing. The mechanical attributes of the resulting blends were systematically examined using tensile, compressive, flexural and impact testing and were conducted according to ASTM standard methods. To obtain structural and thermal details of the blends, X-ray diffraction (XRD) was used to investigate crystallinity, thermogravimetric analysis (TGA) was used to examine thermal stability and scanning electron microscopy (SEM) was performed to investigate microstructural morphology and phase distribution in the polymer matrix. These elaborate descriptions offered an integrated overview of how different blend ratios influenced the performance and integrity of the composite materials. Findings The incorporation of ABS, PP and PS into PLA diminished tensile, flexural and compressive strength while markedly enhancing impact strength, with the PLA-40/ABS-40/PP-10/PS-10 blend exhibiting the greatest impact resistance (19.85 kJ/m²) and the highest flexural strength was exhibited by the 10 Wt.% PS composite (53.53 MPa). The PLA-42.5/ABS-42.5/PS-15 composition displayed higher thermal stability, as validated by TGA. XRD signals demonstrated an amorphous nature in all blends, but SEM exhibited uniform dispersion with sporadic agglomerates in specific blends, impacting mechanical integrity. Originality/value This research proposes a novel technique to customizing the mechanical and thermal properties of biodegradable PLA by integrating conventional thermoplastics. It contributes to the advancement of cost-effective and sustainable polymer blends for structural and packaging applications.