A green route to UV-curable resins: acrylation and application of hemp seed oil in 3D printing

Abstract

We report the successful synthesis and characterization of acrylated epoxidized hemp seed oil (AEHSO) as a biobased material for novel UV-curable formulations that are alternatives to petroleum-based materials. Several formulations were prepared with trimethylolpropane triacrylate (TMPTA), 1,6-Hexanediol diacrylate (HDDA), and tripropylene glycol diacrylate (TPGDA) using different AEHSO concentrations. Real-time Fourier transform infrared spectroscopy (RT-FTIR) and photo-differential scanning calorimetry (Photo-DSC) were used to determine compatibility and efficiency of AEHSO, and it displayed excellent curing properties. Additionally, contact angle measurements were achieved and displayed hydrophobic characteristics, especially for the HHDA formulation, with a contact angle value reaching 97.9. Dynamic mechanical analysis showed that 20 % AEHSO added formulation had the highest initial storage modulus of 570 MPa at 30 degrees C and 30 % AEHSO added one emerged as the leading formulation, achieving the highest tensile stress (0.90 MPa), force at break (13.85 N), and a glass transition temperature of 83.8 degrees C. A crosslinked gel structure was observed via determination of gel content and swelling studies with varying compositions of AEHSO and commercial acrylates. Gel content increased inversely proportional to the increase in AEHSO amount as expected. In summary, this study successfully demonstrated the use of acrylate hemp seed oil mixtures with various acrylates to create different geometric structures in three-dimensional (3D) printing. These results demonstrate that hemp seed oil-based UV-curable resins are a promising and sustainable alternative to petroleum-derived products for future green technologies.