Coatings derived from novel, soybean oil-based polymers produced using carbocationic polymerization

Abstract

In this study, a process was developed to obtain vinylether-functional monomers containing fatty acid pendent groups directly from soybean oil (SBO) using base-catalyzed transesterification. In addition, a carbocationic polymerization process was developed for the vinylether monomers, which allowed for high molecular weight polymers to be produced without consuming any of the vinyl groups present in the fatty acid portion of the monomers. Compared to SBO, which possesses on average 4.5 vinyl groups per molecule, the polyvinylethers based on the soybean oil-derived vinylether monomers (polyVESFA) possess tens to thousands of vinyl groups per molecule depending on the polymer molecular weight produced. As a result of this difference, coatings based on polyVESFA were shown to possess much higher crosslink density at a given degree of functional group conversion compared with analogs based on conventional SBO. In addition, the dramatically higher number of functional groups per molecule associated with polyVESFA results in gel-points being reached at much lower functional group conversion, which was shown to dramatically reduce cure-time compared with SBO-based analogs. Based on the results obtained, it appears that these new renewable materials may have tremendous commercial utility in the coatings industry.