Aqueous cationic homo- and co-polymerizations of -myrcene and styrene: a green route toward terpene-based rubbery polymers

Aqueous cationic polymerization of -myrcene, a naturally occurring monomer, was performed for the first time using a water-dispersible Lewis acid surfactant combined catalyst (LASC) prepared from ytterbium chloride and a branched sodium dodecylbenzenesulfonate surfactant. At 40 degrees C, poly(-myrcene)s of high molecular weight (M-n up to 150 kg mol(-1)) and low glass transition temperature (T-g < -63 degrees C) were obtained. They possess predominantly 1,4-units (approximate to 43% cis and approximate to 50% trans) and few 3,4-units (approximate to 7%) together with both regular head-to-tail (62-72%) and inverse (5-10% head-to-head and 23-28% tail-to-tail) sequences. The LASC showed also high efficiency in catalyzing the emulsion cationic copolymerization of -myrcene and styrene, affording the synthesis of random copolymers with high molecular weights (M-n from 60 to 120 kg mol(-1)) and single glass transition temperatures (T-g's from -43 to 15 degrees C). Finally, a simple procedure was developed to recover the catalyst from the reaction mixture, which showed high activity in the -myrcene emulsion cationic polymerization even after five successive cycles of extraction.