Thermal and photocuring of an acrylate-based coating resin reinforced with nanosilica particles

A macromonomer, 1,3-bis[(2-hydroxy-3-acrylate)propyloxy]2-hydroxypropane (BHAPP) was prepared by the reaction of acrylic acid with diglycerol diglycidyl ether (DGE) in the presence of triethyl amine as a catalyst. The progress of the reaction was followed by measuring the decrease in intensity of the epoxide absorption peak at 915 cm⁻¹, and structure of BHAPP was characterized by FTIR and ¹H NMR spectroscopy. The effect of nanosilica (NS) particles as catalyst on thermal and photocuring of BHAPP was studied. The photopolymerization was carried out with the visible light using camphorquinone and N,N-dimethylaminoethylmethacrylate (DMAEM) as the photoinitiating system. The kinetic parameters of thermal curing were obtained using nonisothermal differential scanning calorimeter (DSC), and the data indicated that NS particles catalyzed the cure reaction by shifting the exothermic peak toward lower temperatures, decreasing the activation energy (E _a), and increasing the rate constant value. The absorption properties of the cured nanocomposites were also studied in different exposure conditions.