Tunable Stereolithography Photopolymerization Resin for Molding Water-Soluble Cavities

Vat photopolymerization (VP), or stereolithography, is rapidly being adopted as an additive manufacturing (AM) technique that yields parts with high precision and feature sizes below 100 μm. As such, the development of materials for VP is essential for extending this printing technology into a variety of application spaces. In this work, we describe a thermoset acrylate polymer system suitable for fabricating sophisticated parts via vat polymerization (VP) with excellent strength (E = 1500 MPa) and toughness (strain to break = 13%-46%). The printed parts can be formulated to be completely water-soluble for cavity molding applications. While the material does not dissolve in neutral or acidic aqueous conditions, it rapidly dissolves in the presence of base, a property afforded by using methacrylic anhydride as a hydrolytically cleavable cross-linker. Additionally, adjustment of the monomer ratio and cross-linker content in the resin formulation tunes the mechanical properties of the printed polymer. The resulting material is readily processed with vat polymerization additive manufacturing techniques, allowing for direct and rapid construction of intricate and complex parts for applications such as tissue engineering or lost-wax casting.