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

## TL;DR

This study shows how the number of carbon–carbon double bonds in vegetable oils affects the strength and properties of 3D-printed parts made using stereolithography.

## Contribution

The paper introduces a method to tune the mechanical properties of 3D-printed parts by varying the unsaturation levels in vegetable oil-based resins.

## Key findings

- Linseed oil-based parts showed better tensile strength than soybean oil-based parts.
- The degree of unsaturation in oils directly impacts the thermo-mechanical properties of printed parts.
- Blending resins from different oils allows for tuning of final part properties.

## Abstract

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.