Study of High-Performance Protective Coatings of Bio-Based UV-Curable Castor Oil Alkyd Resins Modified by Boron

Abstract In this current research, castor oil based fatty amide (COFA) and monoglyceride (COMG) were synthesized separately in the laboratory and subsequently reacted with itaconic acid to produce alkyd resins named as COFAIA and COMGIA, respectively. Afterwards, a boron based triacrylate monomer, (borane-triyltris(oxy))tris(ethane-2,1-diyl) (BAM) was prepared via esterification of boric acid and hydroxyethylacrylate (HEA), in a molar ratio of 1:3 using p-toluene sulphonic acid (pTSA) as a catalyst. Structural determination of synthesized materials COFAIA, COMGIA and BAM were done by Fourier transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR).Then, using synthesized materials, various UV curable coating formulations were prepared by blending varying compositions of COFAIA or COMGIAwith BAM (0 to 5% in w/w). These compositions were coated as a film on mild steel and wood panels and cured under UV radiations. The cured coatings were evaluated for different properties by performing various tests such as cross-cut adhesion, pencil hardness, gloss test, impact resistance, scratch resistance, and stain test. Chemical resistance was evaluated by immersion method in 2N NaOH, 2N HCl, xylene, and water while anticorrosion property was determined in 3.5% NaCl solution. Thermal stability of synthesized compounds of COFAIA, COMGIA and BAM were studied by thermogravemetric analysis (TGA). Surface morphology and crystallanity of synthesized coating films were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Also, stain property of coatings was carried on coated wood panel. The results show that BAM incorporated UV curable films display superior performance by enhancing studied properties for their coating applications.