Hydrophobization of fully bio-based epoxy polymers using water as solvent: Effect of additives

•Fully bio-based epoxy polymer was prepared using water as the only solvent.•Bio-based additives were used to hydrophobize the hydrophilic-natured polymer.•Combination of three bio-based additives showed best hydrophobic effectiveness.•Incorporation of bio-based additives tends to slightly compromise the curing reaction.•The hydrophobized epoxy coating displayed improved corrosion protection for metals.