Preparation of rosin epoxy soybean oil acrylate with high bio-renewable carbon content for 3D printing

A kind of rosin epoxy soybean oil acrylate (RBAESO) containing high bio-renewable carbon content was synthesized by using rosin and acrylic acid (AA) to react with epoxidized soybean oil (ESO), and the effects of rosin addition amount on the properties of RBAESO resin and its cured film were investigated. The reaction activity between carboxylic acid and the epoxy group was found improved by introducing natural rosin to replace part of AA and increasing the C--C - - C double bond density of the molecular structure. The best prepolymer resin RBAESO15 % performance was obtained with a reaction molar ratio of ESO: AA: Rosin = 1.05:0.85: 0.15. RBAESO-15 % has a viscosity of 16500 mPa & sdot;s. The cured film of RBAESO-15 % displayed high pencil hardness up to H, and 2 mm of flexibility. The introduction of rosin also increased the high bio-renewable carbon content of the resin from 80.3 % to 89.6 % compared to epoxy soybean oil acrylate (AESO). UV cured tested show the C--C -- C double- bond conversion of RBAESO-15 % is about 86.4 %, which is higher than that of AESO, and the tensile strength and elongation at break increased from 3.2 MPa and 7.4 % to 14.4 MPa and 12.1 %, respectively. This indicates that RBAESO displays better coating film performance than those of AESO. In addition, RBAESO-15 % with 2,4,6trimethylbenzoyl-diphenylphosphine oxide (TPO) can be applied to the laser cladding deposition (LCD) 3D printers.