Exploring β-Myrcene Incorporation in Propene Copolymerization Using Half-Titanocene Catalysts

The development of polyolefin from bio-renewables has been considered an important subject in terms of circular economy. In this study, exploring the possibility of β-myrcene (MY) incorporation in propene copolymerization has been studied in the presence of various catalysts: phenoxide-modified half-titanocene, Cp’TiCl2(O-2,6-iPr2-4-C6H3) Cp’ = Cp* (C5Me5), Me3SiC5H4, and ketimide-modified half-titanicene, Cp’TiCl2(N=CtBu2) (Cp’ = Cp*, Cp). Among the complexes tested, the permethylated Cp* catalysts, Cp*TiCl2(O-2,6-iPr2-4-C6H3) and Cp*TiCl2(N=CtBu2), exhibited moderate catalytic activities in the copolymerizations, affording the copolymers up to 3 mol% MY incorporation. The other catalysts showed negligible activity in the attempted copolymerizations. The resulting copolymers were amorphous and possessed sole glass transition temperatures (Tg), suggesting uniform compositions; the Tg values decreased with increasing comonomer (MY) content, reaching values as low as −17 °C. The results introduce valuable insights into the structure–property relationships of myrcene-based copolymers and pave the way for the future designs of tailored molecular catalysts for the synthesis of biobased elastomers.