Evidence of intramolecular cyclization in copolymerization of ethylene with 1,3-butadiene: Thermal properties of the resulting copolymers

Ethylene and butadiene were copolymerized with a silylene-bridged bis(fluorenyl) complex {[Me2Si(C13H8)(2)]-NdCl} (1) in combination with various alkylating agents (BuLi/AlH(iBu)(2), (Bu)MgCl, Mg(Bu)(Oct)). Copolymers have a unique microstructure since they contain 1,2-cyclohexane rings and unsaturations along the polymer chain. An intramolecular mechanism was proposed for the formation of six-membered rings. The influence of these cyclic structures on thermal properties of the copolymers has been investigated.