Permeability of 3D Printed Acrylate Rubbers

The versatility of vat photopolymerization additive manufactured (VPAM) elastomers garners much interest in the production of medical supplies and microfluidic devices. However, little research has characterized the liquid barrier properties and chemical resistance specifically related to these emerging acrylate-based VPAM polymers. Herein, we describe a systematic approach to studying the structure–property relationships for a series of 3D printable elastomers from commonly used monomers and crosslinkers, including n-butyl acrylate (BA) and 2-hydroxyethyl acrylate (HEA). Polymer samples showed elongations-to-break between 200%–400% and Young's moduli between 0.4–0.6 MPa. The study helps to develop a picture of the chemical space inhabited by these model systems via permeability experiments and relation to Hansen solubility parameters (HSPs). The permeability of the tested solvents dimethyl sulfoxide (DMSO), dimethylformamide (DMF), pyridine, isopropanol (IPA), and tetrahydrofuran (THF) was related to the composition and increased water uptake of the materials. As the weight percent of HEA increased in the polymer composition, the permeability of all solvents increased. The magnitude of the permeability depended on solvent interactions with water, quantified by HSPs, and was independent of polymer composition. THF exhibited the highest permeability through the polymer membranes due to its low HSP. The formulated elastomers represent modular VPAM materials accessible with current commercial 3D printing technology that can be deployed for specific applications.