Abstract
Lactic ester of maleoabietic acid (RAMALA) was obtained by chemical reaction between Diels-Alder adduct of resin acids with maleic anhydride (RAMA) and lactic acid (LA). The obtained product was characterized by elemental analysis and by spectroscopic methods (IR and NMR). Curing reaction of three epoxy resins (diglycidylether of bisphenol A (DGEBA), diglycidyl ether of hydroquinone (DGEHQ) and diglycidylaniline (DGAN), with (RAMALA) in the presence of triethylbenzylammonium chloride (TEBAC) as catalyst was examined by differential scanning calorimetry (DSC) at different heating rates. Using the literature methods the kinetic parameters of crosslinking reactions were obtained. The activation energies of the curing reactions varied in the range of 48 to 85 kJmol-1 depending on epoxy systems. The thermal behaviour of cured products was also investigated using dynamic thermogravimetric analysis (TGA) technique. The cured products present good thermal stability and the activation energies of the degradation process exhibit values between 82 to 155 kJ×mol-1. Keywords: Diels-Alder adduct of resin acids, lactic ester of Diels-Alder adduct of resin acids with maleic anhydride ,epoxy resin, crosslinking reactions, thermal properties