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A new method was presented for preparing (co-)polyethylene with broad molecular weight distribution (MWD) and high molecular weight employed by the novel heterogeneous Ziegler–Natta catalysts via one-pot strategy. The preparation of these catalysts involved the introduction of alkoxy silane compounds as electron donors. The influences of the electron donors structure, as well as polymerization conditions such as temperature, molar ratio of Al/Ti, ethylene pressure and the concentration of 1-hexene in feed on the polymerization performance for ethylene (co-)polymerization, were investigated. The morphology of the catalyst particles was characterized by SEM and Ti content of these catalysts was characterized by ICP. The GPC results showed that the obtained homopolyethylene and ethylene/1-hexene copolymer had the widest molecular weight distribution up to ca 50 when diethoxy-isopropoxy-(t–butoxy)-silane (ED3) was used as internal electron donor. The 13 C NMR and FT-IR analysis indicated that these catalysts efficiently catalyzed the copolymerization of ethylene with 1-hexene.

The copolymerization of styrene with ethyl- ene was promoted by CpTiCl3/BDGE/Zn/MAO catalyst system combining free radical polymerization with coordi- nation polymerization via sequential monomer addition strategy in one-pot. The effect of polymerization condi- tions such as temperature, time, ethylene pressure, and Al/Ti molar ratio on the polymerization performance was investigated. The hydroxy-functionalized aPS-b-random copolymer-b-PE triblock copolymer was obtained by sol- vent extraction and determined by GPC, DSC, WAXD, and 13 C-NMR. The DSC result indicated that the aPS-b- random copolymer-b-PE had a Tg at 87 � C and a Tm at 119 � C which attributed to the Tg of aPS segment and the Tm of PE segment, respectively. The microstructure of the hydroxy-functionalized aPS-b-random copolymer-b-PE was further confirmed by WAXD, 13 C-NMR, and 1 H-NMR analysis; and these results demonstrated that the obtained block copolymer consisted of aPS segment, S-E random co- polymer segment, and crystalline PE segment. The connec- tion polymerization of the hydroxy-functionalized aPS with random copolymer-b-PE was revealed by GPC results. V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 120: 3171-3179, 2011

The star-shaped polymethylmethacrylate (PMMA) was synthesized via radical polymerization promoted by metallocene complexes in the presence of initiator of tetra(2,3-epoxy propoxy)silane (Is) and reducing agent Zn. The effect of temperature, time, molar ratio of monomer to initiator, and the structure of metallocene complexes on the polymerization performance was investigated. The structure and properties of the obtained polymer were characterized by gel permeation chromatography, multiangle laser light scattering, 1H NMR, 13C NMR, and WAXD. The results indicated that the obtained polymer was atacticspecific and featured narrow molecular weight distribution (1.30–1.57). Star-shaped organosiloxane-functionalized PMMA was produced. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Comparison with the conventional Ziegler–Natta catalyst TiCl4/MgCl2 (I), the modified supported Ziegler–Natta catalysts (iso-PentylO)TiCl3/MgCl2 (II) and (BzO)TiCl3/MgCl2 (III) were prepared as efficient catalysts for copolymerization of ethylene with 1-octene. The complexes (II) and (III) were desirable for the production of random ethylene/1-octene copolymers coupled with higher molecular weight, higher comonomer incorporation within copolymer chain and good yield even at high temperature 80 °C and fairly low Al/Ti molar ratio of 100. The effects of catalysts ligands, Al/Ti molar ratio, polymerization temperature, as well as concentration of 1-octene on the catalytic activity, molecular weight and microstructure of the copolymer were investigated in detail. The structure and properties of the copolymers were characterized with 13C NMR, GPC, DSC and WAXD. The kinetic results also indicate that these catalysts (II) and (III) show higher catalytic activity and the produced polymers feature higher molecular weight, because of lower ratio of Ktrm/Kp and Ktra/Kp, and higher ratio of Ktra/Ktrm which indicates that chain transfer to cocatalyst is predominant.