Author
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CRIVELLO, JAMES - RENSSELAER POLYTECHNIC |
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Carlson, Kenneth |
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Submitted to: Macromolecular Reports
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/10/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Concerns for air and water pollution arising from the manufacture and use of paints and coatings, inks and adhesives has spurred research to reformulate these products with reduced levels or none of the components, such as organic solvents, that adversely effect the environment when they evaporate. Reformulating with water as a solvent and baking of dry-powder coated items have been successful with some of these products. Formulations containing unique naturally occurring vegetable oils, such as vernonia or euphorbia oils, react with other components to become an integral part of the paint, coating, or plastic in processes that generate no volatiles. We now have found that vernonia and euphorbia oils may be mixed with small amounts of materials called catalysts that, when irradiated with light or high energy beams, cause the oils to instantaneously "dry" or 'Cure" into uniform tough coatings. This new technology allows for higher rates of production of coated items with lower energy consumption in the curing process, which produces no volatile pollutants. Potential benefits from this discovery are new, better, and cheaper consumer items produced by environment-friendly processes. Technical Abstract: Naturally occurring epoxidized triglyceride oils were obtained from two plant sources: Vernonia galamensis and Euphorbia lagascae. The oils were subjected to UV induced cationic photopolymerizations in the presence of a diaryliodonium salt photoinitiator. The rates of the photoinduced cationic polymerization of the oils were investigated as a function of the source of the oil and the concentration of the photoinitiator, and also were compared with a chemically epoxidized triglyceride, epoxidized soybean oil. The natural oils undergo facile polymerization in the presence of 2-4% of the photoinitiator. Rates and extent of polymerization were monitored by observing the disappearance of the 825 cm-1 epoxy band using Fourier transform real-time spectroscopy (RT-RTIR). We observed that a sample of commercially epoxidized soybean oil, despite its higher oxirane content, was substantially less reactive and polymerized to a lesser extent than the vernonia and euphorbia oils. These novel oils show considerable promise for such applications as UV curable coatings, inks and adhesives in low VOC systems. |
