Preparation of isotacticity‐rich poly(tert‐butyl vinyl ether) by the cationic polymerization of tert‐butyl vinyl ether with dimethyl[rac‐ethylenebis(indenyl)]zirconium and tri(pentafluorophenyl)borane

Abstract

Abstracttert‐Butyl vinyl ether (tBVE) was polymerized with the catalyst dimethyl[rac‐ethylenebis(indenyl)] zirconium (ansa‐zirconocene) with tri(pentafluorophenyl) borane [B(C6F5)3] as a cocatalyst. The effects of various polymerization conditions, such as the polymerization time, type of polymerization solvent, polymerization temperature, and catalyst concentration, on the conversion of tBVE into poly(tBVE), its molecular weight and molecular weight distribution, and its stereoregularity were investigated. The maximum conversion of tBVE into poly(tBVE) was over 90% at a polymerization temperature of −30°C with an ansa‐zirconocene and B(C6F5)3 concentration of 3.0 × 10−7 mol/mol of tBVE, respectively. The number‐average molecular weights of poly(tBVE) ranged from approximately 14,000 to 20,000, with a lower polydispersity index (weight‐average molecular weight/number‐average molecular weight) ranging from 1.48 to 1.77, at all polymerization temperatures. The number‐average molecular weight of poly(tBVE) increased with decreases in the polymerization temperature and catalyst concentration. The mm triad sequence fraction of poly(tBVE) polymerized with ansa‐zirconocene/B(C6F5)3 at −30°C was much higher than that of poly(tBVE) polymerized with the B(C6F5)3 catalyst at −30°C, and this indicated that the ansa‐zirconocene/B(C6F5)3 catalyst system affected the isospecific polymerization of tBVE. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008