Acetoacetylated castor oil in coatings applications

The hydroxyl functionalities of castor oil were converted to β-ketoesters by reaction with t-butyl acetoacetate. The reaction is relatively rapid and proceeded to high yield under mild conditions. The resulting acetoacetate esters were used to formulate thermosetting coating compositions. Films were cured at ambient and elevated temperatures using multifunctional amines as crosslinkers. The films obtained had only modest solvent resistance even when cured at elevated temperatures. The pencil hardness of the films was reasonably given the cure level obtained. The 60° glosses of the films and film flexibilities were good.