Synthesis, characterization, and performance evaluation of hard, anticorrosive coating materials derived from diglycidyl ether of bisphenol A acrylates and methacrylates

Diglycidyl ether of bisphenol A acrylate (DAC) and diglycidyl ether of bisphenol A methacrylate (DMAQ were synthesized by the reaction of an epoxy [diglycidyl ether of bisphenol A (DGEBA)] with acrylic acid and methacrylic acid, respectively. The synthesized resins were characterized by determination of the acid, hydroxyl, and saponification values. Structure elucidation was done by gel permeation chromatography, Fourier transform infrared spectroscopy, H-1-NMR spectroscopy, and C-13-NMR spectroscopy. DACs were cured with melamine formaldehyde resin at low pH values. The pH of the resin systems was adjusted with phosphoric acid. The coatings of these systems were formed on mild steel specimens for physicomechanical and chemical/corrosion-resistance performance. The coatings of DAC and DMAC showed excellent scratch hardness and good impact-resistance performance. The coatings of DMAC showed better performance than DAC with respect to chemical and corrosion resistance. Thermo-gravimetric analysis and differential scanning calorimetry were used to investigate the thermal stability and curing behavior of these systems. DAC showed a little higher glass-transition temperature than DMAC and also showed a higher thermal resistivity. (C) 2004 Wiley Periodicals, Inc.