Curing and thermal behavior of resin matrix for composites based on epoxidized soybean oil/diglycidyl ether of bisphenol A

The influences of different amounts of epoxidized soybean oil (ESO) on the curing kinetics and thermal properties of diglycidyl ether of bisphenol A (DGEBA) epoxy resin, cured with p-aminobenzoic acid (p-ABA) were investigated by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), near infrared chemical imagistic (NIR-CI) and thermogravimetry (TGA). SEM and NIR-CI data reveal that a statistical distribution in the structure of DGEBA/p-ABA/ESO was obtained. The DSC data showed that the activation energy of the curing reaction increases with ESO content increase. On the other hand the glass transition temperature decreases. Also, the activation energy of the thermal degradation decreases with ESO amount increase.