Green nanocomposite coatings based on renewable plant oils have been developed. An acid-catalyzed curing of epoxidized plant oils with 3-glycidoxypropyltrimethoxysilane produced transparent nanocomposites. The hardness and mechanical strength improved by incorporating the silica network into the organic polymer matrix, and good flexibility was observed in the nanocomposite. The nanocomposites showed high biodegradability.