Curing and thermal degradation of diglycidyl ether of bisphenol A epoxy resin crosslinked with natural hydroxy acids as environmentally friendly hardeners

The paper presents the curing of diglycidyl ether of bisphenol A (DGEBA) with two natural hydroxy acids and the thermal behavior of the cured products. The kinetics of the curing reactions were evaluated from the differential scanning calorimetry (DSC) curves using Ozawa, Kissinger methods and “Thermokinetics-3” software (Netzsch). Thermal decomposition behavior of the cured products up to 600 °C (in nitrogen) was made using simultaneous TG/FT-IR/MS technique. The kinetic parameters were obtained using the same software which shows that the thermal degradation takes place in three or four consecutive steps. The chemical composition of gases evolved at the thermal decomposition has been identified using FT-IR and MS techniques. The main products are: water, carbon dioxide, acids, anhydrides, aliphatic and aromatic hydrocarbons.