3D Printing as Innovative Approach in the Valorization of Polymer Blends

Abstract

Polymer blends have been extensively studied as a means to tailor material properties by combining the advantages of different thermoplastic polymers. Nevertheless, the inherent immiscibility of most polymers often leads to phase‐separated morphologies with poor interfacial adhesion, thereby limiting mechanical performance. The recent expansion of additive manufacturing, particularly material extrusion (MEX), has renewed interest in polymer blends, as this technology offers opportunities for material customization and sustainability. However, MEX imposes strict requirements on material processability, including stable melt flow, resistance to repeated thermal cycles, and consistent filament quality, which make processing polymer blends particularly challenging and partly explains their limited adoption compared to single‐polymer systems. Despite these limitations, recent studies highlight the significant potential of polymer blends in MEX through the implementation of compatibilization strategies, morphology control, and process optimization. This review provides a comprehensive overview of recent advances in polymer blends for MEX‐based 3D printing. It first examines the limitations of conventional polymers and polymer blends used in 3D printing, followed by an analysis of blend systems reported in the literature, identifying both promising formulations and those requiring further investigation. Key challenges related to material selection, processing, printing parameters, and the properties of printed parts are discussed, including miscibility, rheology, interlayer adhesion, and porosity.