An environmentally benign room temperature aqueous homo‐ and copolymerization of styrene and methylmethacrylate catalyzed by [Cp₂TiCl₂]/NaBPh₄

Abstract

[Cp2TiCl2] has been found to be an effective precatalyst for room temperature aqueous homo‐ and copolymerization of methyl methacrylate and styrene in the presence of a cocatalyst, NaBPh4 and an emulsifier, sodium n‐dodecyl sulfate. The polymers obtained are of high molecular weight with low molecular weight distribution. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6496–6503, 2009

Synthesis of high molecular weight polymer nanoparticles by [Cp2ZrCl2] catalyzed emulsion polymerization

“…However, in the presence of NaBPh 4 it can easily copolymerize the monomers. The stereoselectivity of the present catalytic system in copolymerization reaction is much better as we could obtain copolymer containing up to 77% cosyndiospecific MMA units whereas no such stereoselectivity could be observed in case of [Cp 2 TiCl 2 ] + NaBPh 4 catalyzed copolymerization 12…”

“…So in our earlier works we suggested that, a cationic species, [Cp 2 MOH] + (M = Ti or Zr) is the active catalyst and this cation is stabilized by sodium n ‐dodecyl sulfate anion 10, 11. Recently we have reported the effect of various large, soft and noncoordinating anions on the catalytic activity of Cp 2 TiCl 2 in aqueous medium 12. Similar studies have been done on Cp 2 ZrCl 2 in presence of various counter‐anions namely ClO 4 − , PF 6 − , BPh 4 − , BF 4 − , etc., and the results are summarized in Table 1.…”

“…4). As mentioned earlier, we have already reported room temperature aqueous emulsion polymerization of styrene and MMA using Cp 2 TiCl 2 as catalyst and NaBPh 4 as cocatalyst 12. We were interested in studying the properties of the polymer latex produced by Cp 2 TiCl 2 catalyzed reactions.…”

“…However, in these reactions longer reaction time, typically 12 to 15 hours, as well as higher temperature (70–90 °C) was required and we could not achieve copolymerization of these two monomers using Cp 2 ZrCl 2 under these reaction conditions. Recently we have succeeded in developing a catalytic system for room temperature aqueous homo‐ and copolymerization of styrene and methyl methacrylate using Cp 2 TiCl 2 as catalyst and NaBPh 4 as cocatalyst 12. We were interested in studying the nature and size of the of the latex particles as well as efficacy of Cp 2 ZrCl 2 as catalyst for room temperature aqueous emulsion polymerization.…”

Aqueous emulsion homo- and copolymerization of 1,3-dienes and styrene in the presence of Cp2TiCl2

“…[28][29][30][31] Organo-titanium (III) species, which are readily obtained by the reduction of inexpensive Cp 2 TiCl 2 with Zn, have been reported to catalyze styrene, substituted styrene or conjugated diene living radical polymerization initiated by epoxides, peroxides or aldehydes. [28][29][30][31] In the literature, a few articles by Bhattacharjee et al [32][33][34][35][36] have described the use of Cp 2 MCl 2 (with Cp ¼ cyclopentadienyl and M ¼ Ti, Zr) as an active catalytic precursor for the aqueous emulsion homopolymerization of styrene and methylmethacrylate. This Cp 2 MCl 2 -catalyzed reaction produced stereoirregular polymers that had high molecular weights.…”