Castor oil-based polyfunctional acrylate monomers: Synthesis and utilization in UV-curable materials

[Display omitted] •A new castor oil-based polyfunctional acrylate was developed as UV-curable diluent.•It showed good miscibility with the oil-based prepolymer (AESO) after UV curing.•It prevented the decrease of biobased content for the UV-cured biomaterials.•It inhibited the increase of volumetric shrinkage for the biomaterials.•It exhibited great potential as alternative to the petroleum-based diluent (TMPTA). A new polyfunctional acrylate monomer (COPERAA) was synthesized from castor oil and utilized as a sustainable reactive diluent for UV-curable materials. Firstly, experimental conditions for the synthesis of the monomer were optimized and its chemical structures were confirmed by FT-IR, 1H NMR, and ESI–MS. Subsequently, the effect of COPERAA on biobased content, viscosity, and volumetric shrinkage of the obtained AESO resins were studied. After that the effect of COPERAA on thermal, mechanical, coating, and swelling properties of the resulting UV-cured bioresins were investigated. Furthermore, UV-curing behaviors of the resultant bioresins were evaluated by real-time IR. Compared with the petroleum-based trimethylolpropane triacrylate (TMPTA) diluent, the biobased COPERAA diluent showed better performance on the biobased content, volumetric shrinkage, adhesion, and final CC conversions of the resulting AESO materials and better compatibility with the AESO prepolymer. Therefore, the developed oil-based diluent shows promise to be applied in UV-curable materials.