Butadiene-isoprene copolymerization with V (acac)3-MAO. crystalline and amorphous trans-1,4 copolymers

Butadiene-isoprene copolymerization with the system V(acac)(3)-MAO was examined. Crystalline or amorphous copolymers were obtained depending on isoprene content. Both butadiene and isoprene units exhibit a trans-1,4 structure and are statistically distributed along the polymer chain: Polymer microstructure, comonomer composition, and distribution along the polymer chain were determined by C-13 and H-1 NMR analysis. The thermal and X-ray behaviors of the copolymers were also investigated and compared with results from solid-state 13C NMR experiments