Syndio-and cis-1,4 Dually Selective Copolymerization of Polar Fluorostyrene and Butadiene using Rare-earth Metal Catalysts
writer：Yuanhao Zhong Chunji Wu and Dongmei Cui
keywords：Dually Selective, Fluorostyrene
source：期刊
Issue time：2020年
Synthesizing functional butadiene-styrene rubber through coordination polymerization is a
theoretical challenge of polymer science, since functional monomers are usually poisonous to the applied catalysts. Herein, we report the coordination copolymerization of polar para-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(η3-C3H5)2 (Ln = Sc (2a), Lu (2b))]. Strikingly, complexes 2a and 2b performed dual >99% syndio- and >95% cis-1,4 regio- selectivities and showed obvious characteristics of living polymerization. The insertion of pFS can be facilely tuned in a full range of 0-100% by changing the pFS-to-BD fed ratio. Diblock
P(pFS-BD) copolymers were isolated by one-pot loading monomers and the kinetics study of the copolymerization reaction revealed that BD had privilege to coordinate to the active metal center. Interestingly, the polymerizations of BD and pFS via pulse loading of BD afforded multi-block copolymers of a novel type of fluoro styrene-butadiene rubber with high thermal stability (Td = 368oC). The microstructures of resultant copolymers were confirmed by 1H and 13C NMR measurements and different phase morphologies of the di- and multi-block polymers were displayed through atomic force microscopy (AFM).