| Abstract: | Vinyl ester resins V1, V2 & V3 of acid value (～6 mg KOH g?1 solid) were synthesized using bisphenol-A epoxy and acrylic acid in the presence of triethyl-, tripropyl- and tributyl-, amines in 210, 270 and 340 minutes, respectively. The synthesized resins were characterized by FTIR spectroscopy and a new peak at 2360 cm?1 was observed which is due to attachment of amines to resin structure by hydrogen bond. The curing behavior of synthesized resin containing 40% styrene (w/w) and 2% benzoyl peroxide was studied using DSC technique and found to be affected by presence of amines. Activation energy and frequency factor for the curing reaction increases from 14 Kcal mol?1 to 23 Kcal mol?1. Rheological behavior of resins containing 40% styrene was studied using a Haake Rotovisco RV20 viscometer, and viscosity was found to increase with shear rate up to 200 sec?1. The average values of activation energy at constant shear stress (6-15 Pa) were 12.94, 13.20, 13.70 Kcal mol?1 for V1, V2 and V3, respectively. The activation energy at constant shear rate decreases with an increase in the shear rate. |
