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Stereoselective Polymerization of an Aromatic Vinyl Monomer to Access Highly Syndiotactic Poly(vinyl alcohol)
Author(s) -
Huang Jianming,
Jiang Yang,
Zhang Zhen,
Li Shihui,
Cui Dongmei
Publication year - 2020
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.202000038
Subject(s) - vinyl alcohol , tacticity , polymer chemistry , tetrahydrofuran , monomer , polymerization , chemistry , vinyl polymer , alcohol , polymer , organic chemistry , solvent
Streoregular poly(vinyl alcohol) is hard to obtain because vinyl alcohol is unstable relative to its tautomer acetaldehyde, and the monomer precursor vinyl ester is poisonous to the coordination catalyst. Herein, the coordination polymerization of 2‐vinyl‐2,1‐borazanaphthalene (BN2VN) is reported by the linked or unlinked half‐sandwich ligands attached scandium precursors ((FluSiMe 3 )Sc(CH 2 SiMe 3 ) 2 (THF) (THF = tetrahydrofuran, 1) , (FluCH 2 CH 2 ‐NHC‐R)Sc(CH 2 SiMe 3 ) 2 (THF) (R = mesityl 2 , i Pr 3 , Me 4 ), and (FluCH 2 Py)Sc(CH 2 SiMe 3 ) 2 ( 5 ) for the first time. Among these precursors, complex 5 converts 600 equivalents of BN2VN into polymer within 5 min to reach an activity as high as 8.99 × 10 5 g mol Sc −1 h −1 . The resultant products show excellent syndiotacticity and melting temperatures above 300 °C, which can be transferred to syndiotactic poly(vinyl alcohol) with 90% rr triad content by postpolymerization oxidation.