Syndio-andcis-1,4 dually selective copolymerization of polar fluorostyrene and butadiene using rare-earth metal catalysts

Synthesizing functional butadiene-styrene rubber through coordination polymerization is a theoretical challenge for polymer science, since functional monomers usually deactivate to the applied catalyst. Herein, we report the coordination copolymerization of polarpara-fluorostyrene (pFS) and butadiene (BD) using pyridyl-methylene-fluorenyl supported complexes [(Py-CH2-Flu)Ln(CH2SiMe3)(2)(THF)(n)(Ln = Sc (1a),n= 0; Ln = Lu (1b),n= 1)] and pyridyl-cyclopentadienyl supported complexes [(Py-Cp)Ln(eta(3)-C3H5)(2)(Ln = Sc (2a), Lu (2b))]. Strikingly, complexes2aand2bexhibited dually >99% syndio- and >95%cis-1,4 regio- selectivities and showed obvious characteristics of living polymerization. The insertion ofpFS can be facilely tuned in the full range of 0-100% by changing thepFS-to-BD feed ratio. Diblock P(pFS-BD) copolymers were isolated by concurrent addition of monomers and the kinetics study of the copolymerization reaction revealed that BD had the privilege to coordinate to the active metal center. Interestingly, the polymerizations of BD andpFSviapulse loading of BD afforded multi-block copolymers of a novel type of fluoro styrene-butadiene rubber with high thermal stability (T-d= 368 degrees C). The microstructures of resultant copolymers were confirmed by(1)H and(13)C NMR measurements and different phase morphologies of the di- and multi-block polymers were displayed through atomic force microscopy (AFM).