Synthesis of a polydimethylsiloxane macromonomer and its copolymerization with ethylene

Abstract An allyl‐terminated polydimethylsiloxane (PDMS) macromonomer was synthesized by anionic polymerization of hexamethylcyclotrisiloxane (D 3 ) initiated by allyllithium. The molecular weight (MW) of the macromonomer was consistent with that calculated from the ratio of the monomer consumed to the amount of the initiator used, and the molecular weight distribution (MWD) of the macromonomer was narrow. Graft copolymers with polyethylene backbone and uniform PDMS grafts, PE‐ g ‐PDMS, were prepared by copolymerization of the macromonomer with ethylene using VOCl 3 /Et 2 AlCl as the catalyst. Under the copolymerization conditions, the scission of SiOSi bonds by the catalyst is negligible, so that MW and MWD of the PDMS grafts could be considered to be the same as those of the original PDMS macromonomer.