Styrene-vinylferrocene random and block copolymers by TEMPO-mediated radical polymerization

TEMPO-mediated free radical polymerization was employed for homo- and copolymerization of vinylferrocene (Vfc). Homopolymerization of Vfc resulted in relatively narrow polydispersities ((M) over bar(w)/(M) over bar(n) = 1.24-1.8), however, molecular weights were limited to 4800. Copolymerization with styrene afforded random copolymers with molecular weights ((M) over bar(n)) up to 10000, narrow polydispersity (1.2 < (M) over bar(w)/(M) over bar(n) < 1.4) and up to 42 mol-% Vfc. Block copolymers with PS block and P(S-co-Vfc) block with molecular weights (M,) in the range of 9000 to 17600 ((M) over bar(w)/(M) over bar(n) < 1.3) were also prepared with up to 17 mol-% vinylferrocene. DSC revealed two glass transition temperatures (T-g) evidencing phase separation.