Direct ink writing‐based additive manufacturing of styrene‐isoprene‐styrene block copolymer

Abstract

AbstractThermoplastic elastomer (TPE) is a hybrid polymeric material with immense potential for industrial application due to its unique elasticity, processability, and excellent mechanical properties. However, 3D printing of TPEs using fused deposition modeling (FDM) is challenging due to their poor layer coalescence, high melt viscosity, and weak column strength. In the present work, styrene‐isoprene‐styrene (SIS) block copolymer, a commercially available TPE material, was successfully 3D printed using a direct ink writing (DIW)‐based additive manufacturing process to enhance its design flexibility. The rheology of the prepared inks has a great influence on the printability, layer formability, and resolution of the 3D printed parts. Hansen's solubility criteria were used exclusively, to investigate the most suitable solvent to prepare the inks for the DIW technique, implying better solubility of toluene than THF. This is in line with experimental results that the 3D printed specimens from SIS/toluene inks demonstrate higher stretchability, elastic modulus and tensile strength over the 3D printed specimens from the SIS/THF inks. It has been shown that the selection of a suitable ink and the optimum level of SIS concentration is essential for the successful fabrication of parts using DIW to make them suitable for end use.Highlights The DIW process has been investigated for 3D printing of SIS block copolymers. The rheology of the developed inks has a great influence on printability and layer formability. The 3D printed samples showed high elongation at break, elastic modulus, and tensile strength.