Benzophenone‐functionalized, starlike polystyrenes as organic supports for a tridentate bis(imino)pyridinyliron/trimethylaluminum catalytic system for ethylene polymerization

Abstract

Starlike polystyrenes composed of a microgel core and arms terminated with benzophenone groups were used as organic supports for a tridentate bis(imino)pyridinyliron catalyst for ethylene polymerization in the presence of trimethylaluminum as a cocatalyst. The microgels were synthesized by the atom transfer radical polymerization of styrene initiated by 4‐(1‐bromoethyl)‐benzophenone, with divinylbenzene as the crosslinker. The bromine polystyrene chain ends prevented the ethylene polymerization reaction and had to be removed. This was readily achieved with Cu0 together with dodecanethiol as a transfer agent. When used as supports in the presence of trimethylaluminum and 2,6‐bis[1‐2,6(diisopropylphenyl)imino]ethylpyridynyl iron, these bromine‐free, functionalized polystyrene stars enabled the production of polyethylene beads of a spherical morphology and high bulk density with a catalytic activity similar to that under homogeneous reaction conditions. Moreover, the molar mass distribution of the polyethylene was narrow, suggesting limited transfer to trimethylaluminum. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6997–7007, 2006

Synthesis mechanisms of poly[styrene‐co‐(acrylic acid)]‐supported TiCl4 catalysts modified by magnesium compounds

“…[11][12][13] Researchers usually use linked polystyrene beads to support active catalysts. The homogeneous distribution of active sites is difficult to achieve due to the limitation of diffusion inside the polymer particles.…”

Functional Star‐Like Polystyrenes as Organic Supports of MeDIP(2,6‐iPrPh)2FeCl2 Catalyst Toward Ethylene Polymerization

“…[26,27] On the basis of these results, we have extended our approach toward novel organic supports, by designing functional star-like PS bearing either a BZ moiety or a BA function at each PS branch-end. [28] The latter were then reacted with TMA to directly form alkoxide aluminum-based species at the periphery of the star-like microgel. The synthesis of such ''active supports'' and their capacity to activate MeDIP(2,6-iPrPh) 2 FeCl 2 catalyst, toward ethylene polymerization are discussed in the second part of this manuscript.…”

“…The substitution reaction . On the basis of these results, the bromine atoms present at the core of the PS [28] stars have been eliminated.…”

“…The three initiators a-OMe, v-2-bromoisobutyrate tri(ethylene oxide) 1, [21] a-OH, v-2-bromoisobutyrate tri(ethylene oxide) 2, [21] and 4-(1-bromoethyl)-benzophenone 3 [28] as well as the corresponding linear polystyrene macroinitiators were synthesized according to the quoted papers, respectively.…”

“…The star-like polystyrene with arms terminated by either CH 3 O-(EO) 3 sequence, [21] HO-(EO) 3 sequence, [21] or benzophenone functions [28] were synthesized following the same procedure as previously described.…”