Novel biobased dual-cure coating system

Sucrose esters consisting of acetoacetates and fatty acids were invented as novel biobased amine-cured and autoxidation dual-cure coating systems, in the presence of diamine crosslinker and metal salt driers. Acetoacetylated sucrose soyate (ASS) was an intramolecular system containing both acetoacetates and fatty acids in the same molecule. Miscible bicomponent blends, made of ASS and partially enamine alkyl substituted acetoacetylated sucrose (p-EAS), was an intermolecular curing system. Compatibility between the two components was achieved by reacting acetoacetylated sucrose (AS) with alkyl amines, in which the compatibility could be adjusted by either the alkyl chain length or the degree of enamine alkyl substitution, DES. Sucrose esters were characterized by gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and differential scanning calorimetry (DSC). The properties and drying times of coatings cured through autoxidation, amine-acetoacetate reactions, and by dual-curing were studied. It was found that acetoacetate chemistry improved the attributes of sucrose ester of fatty acids in ambient curing conditions, as well as providing dual-cure coatings having a good balance of properties.