Plant oils are composed of triglycerides with varying amounts of unsaturation in the fatty acid pendant chains. Depending on the level of unsaturation, plant oils may be classified as drying, such as linseed oil, semi-drying, such as soybean oil, or non-drying oils, such as olive oil. In this study, vinyl monomers such as styrene, methyl methacrylate, and vinyl acetate were copolymerized with the acrylate derivatives of the three plant oils mentioned previously. It was hypothesized that vinyl monomer solubility in water can have a great effect on the mechanism of particle nucleation and growth, and ultimately the kinetics of the copolymerization reaction. On the other hand, it has been observed that the rate of copolymerization is inversely proportional to the level of unsaturation present in the system from the plant oil comonomers. This effect is evidently caused by chain transfer reaction to the allylic double bonds in the pendant chains of the plaint oil monomers. For example, in copolymerizations of styrene, the effect of chain transfer is less expressed when the concentration of plant oil comonomer is varied. However, in reactions where the vinyl monomer has greater water solubility, such as vinyl acetate, the reaction rate is retarded to a far greater extent with changes in plant oil-based monomer concentrations. Based on these observations, it can be concluded that not only does the solubility of the vinyl monomer in water contribute to the changes in reaction kinetics, but the radical reactivity should also be considered. For more water soluble vinyl monomers, there is a greater chance that there are two mechanisms of particle nucleation and growth, both in the micelles and in solution. Hence, radical reactivity might contribute more through the “in solution” portion of the reaction.

Effect of plant oil unsaturation on emulsion copolymerization with vinyl monomers

253rd National Meeting (2017)

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