Functionalized Star‐Like Polystyrenes as Organic Supports of a Tridentate Bis(imino)pyridinyliron/Aluminic Derivative Catalytic System for Ethylene Polymerization

Abstract

Summary: Star‐like polystyrenes composed of a microgel core with arms functionalized with a few hydroxy‐ or methoxy‐ended ethylene oxide units were used as organic supports for a tridentate bis(imino)pyridinyliron catalyst towards ethylene polymerization. When used as supports of 2,6‐bis[1‐2,6(diisopropylphenyl)imino]ethylpyridynyl iron dichloride in the presence of various alkylaluminium compounds, the supported catalysts enabled the production, with a high catalytic activity, of polyethylene beads of a spherical morphology and high bulk density. A good control of the polyethylene molar mass distribution could also be achieved, which was explained by a lowering of the transfer reaction to the aluminium derivative, as compared to homogeneous conditions.SEM image of PE particles prepared in the presence of trimethylaluminium supported on a PS microgel with an iron catalyst (TMA/Fe = 800).imageSEM image of PE particles prepared in the presence of trimethylaluminium supported on a PS microgel with an iron catalyst (TMA/Fe = 800).

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

“…Indeed, while iron catalyst supported onto star-like polystyrenes bearing methoxy end-group yield bimodal PE as in homogeneous conditions, iron systems based on polystyrene microgels containing reactive hydroxyl termini yield monomodal PE and enable the suppression of the low PE molar mass fraction. [21] Polymerizations carried out with polystyrene microgels in the presence of TMA as a cocatalyst confirm the results reported above. Although catalytic activities obtained in the presence of these supports [85-570 kg PE/(mol Fe h bar)] are lower than for homogeneous catalysts, narrow MMD PE are formed (runs 4, 5, 8, 9 vs. runs [14][15][16].…”

“…These functional supports have been subsequently used to immobilize at their surface aluminumbased activators (TMA, MAO) and then investigated in the presence of MeDIP(2,6-iPrPh) 2 FeCl 2 for the polymerization of ethylene. [21] Another important domain of investigations concerns the development of effective and low cost activators of metallocene catalyst. Recently, it has been shown that sterically hindered arylaluminates or alkylaluminates and pentafluorophenoxy alumoxane can serve as efficient cocatalysts for metallocene complexes.…”

“…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.…”

Iron-Based and Cobalt-Based Olefin Polymerisation Catalysts

“…In addition to other polystyrene [138] and silica supports [139,140,141,142,143,144] , iron and cobalt precatalysts have been immobilised on calcosilicate [145] , magnesium dichloride [146,147,148,149] , MCM-41 zeolite [150,151] , clay [152] and fluorotetrasilicic mica [153] . Supported systems have also been examined using alternative activators [154,155,156,157,158,159] .…”

ATRP of Silylated Glycerol Monomethacrylate in Organic Medium for Convenient Synthesis of Amphiphilic Copolymers

“…Bifunctional initiator (3a) was prepared following the procedure described by Bouilhac et al [16] and purified according to Lee et al [17] Yield ¼ 54%. Macroinitiator (4) was prepared according to methods described in the literature.…”