The Effect of Radical Compartmentalization on β-Myrcene Thiol–Ene Photopolymerization in Miniemulsion

The use of biobased monomers, such as terpenes, for the partial or complete substitution of fossil feedstocks is a critical step in green polymer chemistry. Herein, the thiol–ene photopolymerization of naturally occurring β-myrcene was carried out in homogeneous and heterogeneous media. The effects of the thiol type, photoinitiator concentration, and reaction time on β-myrcene double bond conversion, molar masses, gel content, and thermal behavior were investigated. Myrcene-based poly(thioethers) were successfully obtained with high gravimetric conversions using all of the techniques; however, they exhibited different characteristics. The compartmentalization effect observed in these thiol–ene photopolymerizations in miniemulsion led to higher reaction rates, gel contents, and molar masses. Furthermore, polymerization in miniemulsion enabled the production of stable submicrometer polymer particles (ca. 200 nm) with low size dispersity. Thiol–ene polymerization is thus a practical approach, where the molar mass and gel content of myrcene-based poly(thioethers) are readily controlled by the polymerization technique, thiol type, photoinitiator concentration, and reaction time.