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A new 100 % bio-based thermosetting coating system was developed from epoxidized sucrose soyate crosslinked with blocked bio-based dicarboxylic acids. A solvent-free, green method was used to block the carboxylic acid groups and render the acids miscible with the epoxy resin. The thermal reversibility of this blocking allowed for the formulation of epoxy-acid thermoset coatings that are 100 % bio-based. This was possible due to the volatility of the vinyl ethers under curing conditions. These systems have good adhesion to metal substrates and perform well under chemical and physical stress. Additionally, the hardness of the coating system is dependent on the chain length of the diacid used, making it tunable.

Ultraviolet-curable nanocomposites containing organically modified nanoclays were prepared to serve as barrier coatings against oxygen and water permeation. A novel in situ synthesis technique was used to produce well-dispersed clays in an unsaturated polyester polymer before crosslinking. The in situ dispersion route was compared with nanocomposites prepared by mixing and sonication for several levels of nanoclay loading (1, 2, 5, and 10 wt %). The comparison of nanocomposite properties prepared from each processing method demonstrated that the in situ preparation technique led to better clay dispersion as verified by transmission electron microscopy. The in situ route for nanoclay dispersion produced nanocomposites with lower water vapor transmission and permeability compared with the sonicated dispersion method. The impact on cure characteristics, mechanical properties, thermal stability, and optical clarity of the nanocomposites were also compared. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012