The relationship between Iowa's main crops and our research group's search for bio-renewable alternatives has produced a large number of research papers focused on the incorporation of vegetable oils into polymers that range from hard and brittle to soft and rubbery, and lately even waterborne coatings, all included in this thesis. Our search has not, however, been limited to corn and soybean oils, we have invested considerable time and effort in looking at other oils, some of which have interesting, naturally-occurring functional groups, like castor oil, or are conjugated, like tung oil. Besides our main interest in vegetable oils, we have succeeded in incorporating agricultural by-products as reinforcing materials in bio-composites, making our materials greener.