Compatibilized ternary blends of polypropylene copolymer, polyethylene, and thermoplastic polyurethane for fused deposition modeling three-dimensional printing technology: preparation, printing, and properties

Abstract

This study investigated the influences of an ethylene-butyl acrylate-glycidyl methacrylate terpolymer (EBA-GMA or G) compatibilizer on printability and properties of fused deposition modeling printing blend filaments of polypropylene random copolymer (PPR), high-density polyethylene (HDPE), and thermoplastic polyurethane (TPU). Six filaments separately fabricated from the blends comprising varying ratios of PPR:HDPE:TPU:EBA-GMA appeared smooth with the average diameter of 1.75 ± 0.03 mm. The results of differential scanning calorimetry and wide-angle X-ray scattering analyses indicated that the addition of EBA-GMA (up to 5 phr) scarcely altered the melting temperatures of both polyolefins, but subsided their degrees of crystallinity, likely caused by the disruption of the structural arrangements of the polyolefin chains by the rubbery EBA-GMA phase. The polarized light optical microscopic images of the filaments isothermally held at different elevated temperatures demonstrated that an increasing content of EBA-GMA integrated not only reduced the sizes of polar TPU and nonpolar polyolefin phases but also raised the number of TPU droplets inside the PPR/HDPE aggregates. The surface morphologies of fractured surfaces of the filaments and their as-printed objects were characterized by scanning electron microscopy and atomic force microscopy; both reduced phase separation and improved interfacial adhesion between the TPU and polyolefin phases were explicitly observed when EBA-GMA was incorporated. The as-printed compatibilized blend objects possessed improved surface topology with the statistically significantly lessened Ra values. Moreover, they exhibited minimized warpage deformation and decreased flexural performances, which was attributed to the elastomeric phase of EBA-GMA. © The Author(s) 2025.