An Experimental and Computational Approach on Controlled Radical Photopolymerization of Limonene

Limonene is a potential candidate for the synthesis of polymers from renewable and non-toxic sources. The synthesis of poly(limonene) via controlled photopolymerization is studied for the first time, both at an experimental and computational level. A kinetic modeling is developed and all unknown parameters are estimated by adjusting them to the experimental data (conversion, molar mass, and dispersity). The reasonable model fit indicates that the proposed mechanism can be considered valid for this process simulation. In that fashion, different reagent ratios are evaluated, as well as simulations for long polymerization times. The experiments provide less than 10% monomer conversion at 40 degrees C, and short times. However, it is possible to identify a reasonable polymerization control (dispersities <1.5). In a complementary way, the simulations allowed to identify a threshold of reagent ratios in order to maintain the polymerization control for conversions around 20%, and at the same time enable monomer conversions at the same level as traditional thermally-initiated radical polymerizations at high temperatures. Therefore, this new route can be a promising alternative for the synthesis of limonene-based polymers. (AU)