Development of novel biobased epoxy films with aliphatic and aromatic amine hardeners for the partial replacement of Bisphenol A in primer coatings

Abstract

New insights into epoxidized linseed oil (ELO) reaction with several amine hardeners for partial replacement of diglycidyl ether of bisphenol A (DGEBA) in coatings formulations are discussed. Thermosets formed by ELO and a variety of hardeners have been examined using 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscope (SEM) techniques. In addition, the mechanical properties, wettability, and swelling of the resulting films have been evaluated. Good properties of ELO cured with diamines, as hexamethylene diamine and p-phenylenediamine, were obtained. Both thermosets offer good impermeability to water, which is higher than that of the commercial epoxy resin, fabricated using DGEBA and polyaminoamide, and an excellent thermal stability. The mechanical behavior is also better than the brittle and rigid films obtained from DGEBA-based resins, films exhibiting the elastic-like behavior of rubber materials. This chapter offers new and promising perspectives in the use of vegetable oils for coatings formulations.