Design and application of tailored resin formulations for 3D printing have emerged as powerful tools for fabricating materials with specific features. Hence, our motivation is to design a straightforward resin formulation that enables the production of elastomeric materials for 3D digital light processing (DLP) 3D printing. In this context, there is significant unexplored potential for the formulation of elastomeric materials using polybutadiene (PB)-based resins. One drawbacks of custom-made elastomer formulations is the elevated viscosity of the resins resulting from high-molecular-mass precursors. Thus, we aimed to design a low-viscosity photopolymerizable resin that enables the fabrication of 3D printed elastomers. Our approach focused on the use of a low-molar-mass PB (5.0 kg mol–1) and butyl acrylate (BA) as the monomer/solvent. As a result, we were able to formulate resins with 20, 30, and 40 wt % PB, successfully printable by DLP by setting the lamp exposure time to ∼30 s per layer (50 μm). Elastomeric printouts were obtained with a satisfactory definition and shape retention for PB20–PB40 formulations. A notable result from this formulation is that no additional cross-linker was required to promote covalent interconnection between PB chains, forming a cross-linked network. This could be evidenced by the measured swelling behavior of the printed specimens and further confirmed by the Flory–Rehner model calculations. Uniaxial tensile tests of the printouts exhibited the expected elasticity, with PB20 printouts showing a 413% strain at break, suggesting that a relatively lower PB content can yield a significant improvement in mechanical behavior. Therefore, we have established the feasibility of designing PB–acrylate resins as a formulation model for DLP 3D printing of elastomers.
Trejo‐Maldonado et al. (Tue,) studied this question.