Effect of Carbon–Carbon Double Bond Content on the Final Properties of Stereolithography 3D-Printed Parts from Vegetable Oil-Based, Acrylated Resins

The increase in the demand for additively manufactured parts and the drive toward a sustainable economy with less environmental pollution has triggered the need for renewable materials for use in 3D printing. This study shows how the final properties of stereolythography (SLA) 3D-printed parts are affected by the number of carbon–carbon double bonds in vegetable oils used to prepare biobased free radical resins. The free radical resins developed in this study contain a minimum of 95 wt% biobased content and are readily polymerizable using a commercial SLA 3D printer. Two distinct vegetable oils, namely soybean and linseed oils, were epoxidized and then acrylated. The epoxidized, acrylated oils and their 50:50 (wt/wt) blend were used to demonstrate the influence of carbon–carbon double bond content on the final properties of SLA 3D-printed parts. The synthetic strategy adopted was successful and showed promise, leading to printed materials with good thermo-mechanical properties. More specifically, it is demonstrated herein that the degree of unsaturation of the oil has a direct impact on the tensile strength of parts printed via stereolithography, and that final properties can be tuned by blending resins prepared from different oils. Ultimately, parts printed with linseed oil displayed better properties than those printed with soybean oil.