Characterization of polypropylene–polyolefin elastomer blends for FDM additive manufacturing

Polypropylene (PP) is extensively utilized in fused deposition modeling (FDM) due to its advantageous properties, yet challenges such as dimensional inaccuracies and warping persist. This work proposes a solution by blending PP with a polyolefin elastomer (POE) and 3D printing with granule-based material extrusion method. By varying POE concentrations (ranging from 10 to 50%), this work comprehensively investigates their effects on printability, stability, adhesion, flexibility, and mechanical performance. The results indicated that higher POE content led to a notable decrease in stiffness, accompanied by improved damping properties and enhanced toughness. Specifically, tensile strength exhibited a reduction of 22% and 31% with each increment in POE content, while compressive strength decreased from 8.27 MPa to 4.56 MPa. Scanning electron microscopy (SEM) analysis underscored the enhanced filament bonding observed with higher POE content. The results of morphology investigation showed that at 10% POE content, well-distributed spherical domains showed excellent elastomer dispersion in the PP matrix, implying potential matrix droplet structure and surface adhesion between phases. By increasing the POE content to 50%, a sea-island structure with a continuous PP matrix and scattered POE domains appeared, which justified the results of increased elasticity and damping factor. These findings highlighted the promising potential of the PP/POE blends in mitigating printing challenges and elevating the performance of the 3D printed parts.