Stereoselective copolymerization of amino-functionalized styrene with butadiene using a half-sandwich scandium complex

Abstract

We report the stereoselective copolymerization of amino-functionalized styrenic monomers, including p-N,N-dimethylaminostyrene (DMAS), p-N,N-diethylaminostyrene (DEAS) and p-N,N-diphenylaminostyrene (DPAS) with butadiene (BD) using a half-sandwich scandium catalyst system (C₅Me₄SiMe₃)Sc(CH₂C₆H₄NMe₂-o)₂/[Ph₃C][B(C₆F₅)₄]. The chain-transfer reaction was efficiently inhibited with the growing steric hindrance of the amino groups. The stereoregular multiblock DEAS-BD and diblock DPAS-BD copolymers were generated with adjustable polymer compositions, controllable molecular weights and narrow molecular weight distributions.