3D printing thermoplastic vulcanizates: Current limitations, innovative solutions, and emerging applications

Thermoplastic vulcanizates (TPVs) are a class of thermoplastic elastomers (TPEs) that achieve a balance between rubber elasticity and thermoplastic processability, which might position them as a sustainable potential replacement for conventional thermoset rubbers. This review covers current state-of-the-art 3D printing TPVs, focusing on the challenges and prospects associated with Material Extrusion (MEX) Methods. Dynamic vulcanization (DV) in processing TPVs increases the dispersion and crosslinking of the elastomeric phase, which might improve both mechanical properties and recyclability. However, the primary obstacles in 3D printing TPVs include filament buckling, phase incompatibility, and high melt viscosity, leading to poor printability and mechanical defects. While there is extensive research on TPVs, these challenges completely prevent their use in additive manufacturing (AM) methods. Various strategies are presented as potential solutions, including adjusting the crosslinking density, incorporating compatibilizers, and using alternative printing methods. While 3D printing of TPVs remains challenging, advancement in material formulation and AM techniques could unlock their full potential in cutting-edge technologies and a greener future. The study highlights the importance of continued research into TPV-based filaments, direct pellet printing, and 4D printing to expand their applications in automotive, biomedical, and soft robotics fields.