Journal of Polymer Science Part A: Polymer Chemistry, Vol.46, No.22, 7299-7309, 2008
Titanium Tetrachloride Supported on Atom Transfer Radical Polymerized Poly(methyl acrylate-co-1-octene) as Catalyst for Ethylene Polymerization
Ethylene polymerizations were performed using catalyst based on titanium tetrachloride (TiCl4) supported on synthesized poly(methyl acrylate-co-1-octene) (PMO). Three catalysts were synthesized by varying TiCl4/PMO weight ratio in chlorobenzene resulting in incorporation of titanium in different percentage as determined by UV-vis spectroscopy. The coordination of titanium with the copolymer matrix was confirmed by FTIR studies. The catalysts morphology as observed by SEM was found to be round shaped with even distributions of titanium and chlorine on the surface of catalyst. Their performance was evaluated for atmospheric polymerization of ethylene in n-hexane using triethylaluminum as cocatalyst. Catalyst with titanium incorporation corresponding to 2.8 wt % showed maximum activity. Polyethylenes obtained were characterized for melting temperature, molecular weight, morphology and microstructure. The polymeric support utilized for TiCl4 was synthesized using activators regenerated by electron transfer (ARGET) Atom Transfer Radical Polymerization (ATRP) of methyl acrylate (MA) and 1-octene (Oct) with Cu(0)/CuBr2/tris(2-(dimethylamino)ethyl)amine (Me6TREN) as catalyst and ethyl 2-bromoisobutyrate (EBriB) as initiator at 80 degrees C. The copolymer poly(methyl acrylate-l-octene; PMO) obtained showed monomodal curve in Gel Permeation Chromatography (GPC) with polydispersity of 1.37 and copolymer composition (H-1 NMR; F-MA) of 0.75. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7299-7309, 2008
Keywords:ARGET ATRP;atom transfer radical polymerization (ATRP);copolymerization;metal-organic catalysts/organometallic catalysts;polymeric support;Ziegler-Natta catalyst;Ziegler-Natta polymerization