Sustainable Myrcene-Based Elastomers via a Convenient Anionic Polymerization

Soluble heterocomplexes consisting of sodium hydride in combination with trialkylaluminum derivatives have been used as anionic initiating systems at 100 °C in toluene for convenient homo-, co- and ter-polymerization of myrcene with styrene and isoprene. In this way it has been possible to obtain elastomeric materials in a wide range of compositions with interesting thermal profiles and different polymeric architectures by simply modulating the alimentation feed and the (monomers)/(initiator systems) ratio. Especially, a complete study of the myrcene-styrene copolymers (PMS) was carried out, highlighting their tapered microstructures with high molecular weights (up to 159.8 KDa) and a single glass transition temperature. For PMS copolymer reactivity ratios, rmyr = 0.12 ± 0.003 and rsty = 3.18 ± 0.65 and rmyr = 0.10 ± 0.004 and rsty = 3.32 ± 0.68 were determined according to the Kelen–Tudos (KT) and extended Kelen–Tudos (exKT) methods, respectively. Finally, this study showed an easy accessible approach for the production of various elastomers by anionic copolymerization of renewable terpenes, such as myrcene, with commodities.

Synthesis of Propylene Oxide – Styrene Copolymers

The copolymerization of propylene oxide (PO) with styrene (St) catalyzed by Maghnite-H+ (Mag-H+) was investigated. Mag-H+, a nontoxic catalyst for cationic polymerization of vinylic and heterocyclic monomers, is a montmorillonite silicate sheet clay. This catalyst was prepared through a straight forward proton exchange process. It was found that Mag-H+ initiates the copolymerization in bulk at room temperature. Various techniques, including H1NMR, 13C-NMR, FT-IR spectroscopy, and Ubbelohde viscometer, were used to elucidate the resulting copolymers' structural characteristics. The effects of the amount of Mag-H+ and propylene oxide were studied. The yield of copolymerization depends on the amount of Mag-H+ used and the reaction time.

Precision ethylene-styrene copolymers through the ring opening metathesis polymerization of 3-phenyl cyclododecenes

Precision polyolefin copolymers were synthesized by ROMP of phenyl-substituted cyclododecenes. Hydrogenation of the polydodecenamers afforded linear low density polyethylenes with a phenyl side chain every twelve backbone carbons.

Vinylboronic acid pinacol ester as a vinyl alcohol-precursor monomer in radical copolymerizations with styrene

The use of vinylboronic acid pinacol ester (VBpin) as a comonomer and post-polymerization oxidation afforded vinyl alcohol (VA)-styrene copolymers that was difficult to synthesize using a typical VA precursor monomer,...