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Study of some parameters on the zirconocene immobilization over silica

“…The silica micrograph shows predominantly round and oval particles with little size variation. Likewise, the polyethylene resin grew as particles of regular round and oval shape, similar to the silica support, in agreement with published results [1,15].…”

“…Furthermore, morphology studies of polymers obtained with metallocenes anchored in different supports [1,[15][16][17] indicated a direct relation between the polymer and support morphology.…”

Effect of Light on the Activity of Metallocene Catalysts in the Gas-Phase Polymerisation of Ethylene

“…However, the reaction conditions used by dos Santos et al were not exactly the same as ours: Al/Zr was 2000, and polymerisation was made in toluene with 1 bar ethylene, and so comparison should be only allusive. Another example of a low Al/Zr-ratio catalyst was presented by Quijada et al [9] They polymerised Ind 2 ZrCl 2 on different silica supports having a similar Al/ Zr to ours of 200. Activities in their experiments were found to be from 82 to 98 kg PE/(mol Zr N h N bar) depending on the catalyst support and zirconium content.…”

Highly Efficient Supported Diimine Ni(II) and Iminopyridyl Fe(II) Catalysts for Ethylene Polymerizations

“…Uniform dispersion of the active components on the SiO 2 surface prevents them from various deactivation processes such as bimolecular deactivation, which is common with homogeneous catalysts. The nonporous nature of silica gel allows the highly efficient activation of all the loaded catalyst during polymerization by diminishing possible diffusion limitation of monomer into the interior pores of the supported catalyst [19]. Thus, the high activity of E may be the result of full activation of the plausible active centers present on the surface of the heterogeneous variant.…”