Synthesis and characterization of epoxy resins containing bismuth

The synthesis of epoxy resins in the presence of Bi as bismuth acrylate (BiA(3)) showed that the properties such as epoxide equivalent weight (eq/100 g), molecular weight, and viscosity (eta(sp)) increased; whereas hydrolyzable chlorine content, hydroxyl content, and refractive index decreased in the presence of BiA(3). The metal forms a complex with ether linkage of epoxy resins, as evidenced from infrared spectroscopy. The presence of Bi in epoxy resins has been confirmed by scanning electron microscopy (SEM) and qualitative analysis. The glass transition temperature (T-g) of epoxy resins containing 1.18 x 10(-5) and 2.8 x 10(-5) molar equivalent of BiA(3) is 131.58 and 190 degrees C, respectively, and is greater than that of blank (130 degrees C). The heat of reactions for epoxy resins containing 1.18 x 10(-5) molar equivalent of BiA(3), calculated by differential scanning calorimetry, is 4.75 J g. (C) 1997 John Wiley & Sons, Inc.