Abstract
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.
Highlights
In the last two decades, on the one side under globalization pressures there has been an extraordinary planetary expansion of plastics and rubbers manufactured for human use (359 million tons in 2018) [1]; on the other side concerns have grown about environmental problems, dwindling petrochemical reserves and climatic changes, due to the accumulation of CO2 in the atmosphere
The scientific community and chemical industry have directed their efforts toward more sustainable processes [2] by using feedstock derived from renewable resources as alternatives to petroleum-based products in order to reduce our dependence on fossil raw materials and their adverse effects on the ecosystems [3,4]
0.5 mL of myrcene was added to reaction mixture and the system was maintained under stirring after equilibration at the desired temperature
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. A temperature-controlled one-pot anionic approach for the preparation of diblock copolymers consisting of PS and PM blocks has been described [41] It has been reported the synthesis of bifunctional (hydroxyl, furan and pyridine group derivatives) monomers dienes obtained from M and their controlled copolymerization with isoprene via catalytic insertion mechanism [42]. The addition of Lewis acid (R3 Al, R3 B, R2 Zn, or R2 Mg), in particular of trialkylaluminium (Et3 Al and i-Bu3 Al) to LiH, NaH and KH, allows for their solubilization in non-polar solvents by formation of bimetallic complexes [51,52,53,54] They are compounds quickly available and stable under inert atmosphere in which one or more hydrogen centers have nucleophilic, basic or reducing properties, commonly used as reducing agents in organic synthesis.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
