Eugenol-Based Siloxane Acrylates for Ultraviolet-Curable Coatings and 3D Printing

To explore more sustainable, safer UV-curable acrylates, a series of bio-based acrylates (SIEEA, SIPEEA, and SIDPEEA) are synthesized from eugenol and siloxanes under mild conditions without any solvent. The molecular structures of the acrylates are characterized, and the acrylates exhibit much lower viscosities than a commercial bisphenol A glycol dimethacrylate (BisGMA) does. The synthesized acrylates can be well cured under UV radiation to form thin films and thick 3D objects. The cured acrylates display significantly improved thermal properties and hydrophobicity and a decreased dielectric constant as low as 3.0 (1 kHz) due to the siloxane backbones. Moreover, they are low in toxicity with the cytotoxicity value above 80%, which is far lower than that of BisGMAs. More interestingly, SIEEA is used as a UV-curable ink and successfully shaped into objects such as chess pieces and a dental model with a high resolution by 3D printing. To summarize, these eugenol-based siloxane acrylates can be readily synthesized, showing a good promise for UV-curable coatings and 3D printing with high thermal stability, low dielectric constant, and low toxicity.