Abstract
Bitumen emulsions are direct emulsions mainly composed of bitumen and an aqueous phase containing a cationic surfactant to stabilize oil droplets in water. Currently used surfactants are usually amino compounds, derived from fossil resources, generally toxic and/or ecotoxic. Therefore, the purpose of this work is to replace these compounds with a range of environmentally friendly products.With this in mind, a controlled and reproducible method of depolymerization of chitosan has been developed. Thus, nitrous deamination was chosen in order to obtain a 5 to 20 units hydrophilic head. Subsequently, amphiphilic chitosan oligomers were obtained by epoxy-amine coupling and amidification. The physicochemical characteristics of these surfactants and their ability to stabilize oil-in-water emulsions were evaluated. Finally, chitosan-based surfactants, potentially 100% bio-based, non-toxic and resulting in stabilization of direct emulsions were synthesized to meet the specifications imposed in this study.