Evaluation of the Effect of Ethanol on the Properties of Acrylic-Urethane Samples Processed by Vat Photopolymerization

Abstract

The aim of the study was to investigate the effect of ethanol on the properties of acrylic-urethane resin products obtained by vat photopolymerization using the masked stereolithography method. The effect of alcohol at concentrations of 15, 25, and 35% in the resin on the chemical structure, weight, thickness of the samples, and mechanical properties in static tabltensile tests performed immediately after printing and one month later were studied. The results obtained were evaluated in terms of the use of ethanol as a cosolvent to help load the resin with agomelatine for the potential of obtaining microneedle transdermal systems. It was shown that in terms of stability of properties, the most favorable system was resin with the addition of alcohol at a concentration of 15%. The greatest changes induced by the presence of the solvent in the resin were observed in the case of tensile properties, where the alcohol caused a decrease in the plasticity of the material, reducing the relative elongation at break from 14% for the pure resin to 4% when the alcohol concentration was 35%. Young’s modulus and tensile strength also decreased with the addition of alcohol by 18% and 31%, respectively, for testable samples with the maximum amount of alcohol in the resin. The deterioration in properties is most likely related to the effect of the solvent on the radical polymerization process of the resin, particularly the phenomenon of chain transfer to the solvent, which is important in view of the intended application of the developed material.