Journal of Molecular Catalysis A: Chemical 240 (2005) 61–66 Supported dichlorobis(3-hydroxi-2-methyl-4-pyrone)Ti(IV) catalysts: Evaluation on ethylene polymerization Paula P. Greco a , Rodrigo Brambilla a , Sandra Einloft a , Fernanda C. Stedile b , Griselda. B. Galland b , Jo˜ ao H.Z. dos Santos b , Nara. R. de S. Basso a,∗ a Laborat´ orio de Organomet´ alicos e Resinas, Faculdade de Qu´ ımica, PUCRS, Av. Ipiranga 6681, Porto Alegre-90619-900, Brazil b Laborat´ orio Cat ´ alise Ziegler-Natta, Instituto de Qu´ ımica, UFRGS, Av. Bento Gon¸ calves 9500–Porto Alegre-91570-970, Brazil Received 14 January 2005; received in revised form 18 June 2005; accepted 20 June 2005 Available online 27 July 2005 Abstract Dichlorobis(3-hydroxi-2-methyl-4-pyrone)Ti(IV) complex was grafted on different inorganic supports, namely different kinds of SiO 2 , MAO-modified silica, MCM-41, Al 2 O 3 , ZrO 2 and MgO. The resulting supported catalysts were shown to be active in ethylene polymerization using methylaluminoxane (MAO) as cocatalyst, most of them being even more active that the homogeneous complex. The highest catalyst activities were observed for the Ti complex supported on SiO 2 948 activated at 450 ◦ C, MCM-41 and Al 2 O 3 . © 2005 Elsevier B.V. All rights reserved. Keywords: Titanium alkoxide; Polyethylene; Polymerization; Supported catalysts; Non-metallocene catalyst 1. Introduction The production of polyolefins in recent years is continu- ously growing. Polyolefins are indispensable materials with certain social impact in countless beneficial ways. World- wide production volume of polyolefins has grown to more than 80,000,000 tonnes/year and is predicted to rise contin- uously at a high rate. Intense research has been carried on olefin polymerization catalysis, in order to develop new cat- alytic systems capable of producing new materials, as well as developing more economic and versatile processes. Since the 1980s, metallocene catalysts have become increasingly important for -olefin polymerization. The met- allocene/methylaluminoxane (MAO) system combines high activity with the possibility of tailoring polymer properties [1]. Depending on the metallocene substituent pattern and symmetry, these catalysts permit a strong control of regio- and stereoregularities and of molecular weight distribution of homopolymers, as well as the synthesis of copolymers ∗ Corresponding author. Tel.: +55 51 3320 3549; fax: +55 51 3320 3612. E-mail address: nrbass@pucrs.br (Nara.R. de S. Basso). with a uniform comonomer distribution. The rapid market penetration of metallocene-based polyethylenes (PE) is due to its high-value attributes, such as greater stiffness and impact strength, greater stretch and puncture resistance and improved sealability. Moreover, polymer properties such as temperature resistance, hardness, impact strength, and trans- parency can be precisely controlled through the metallocene structure [1]. More recently, new generations of non-metallocene cat- alysts have been proposed in the literature [2]. The aim is to develop new systems (the so-called post-metallocene catalysts), which besides not being covered by patents, are capable to afford further improvements in polymer prod- uct properties and production flexibility. While metallocene catalysts are very versatile, the new non-metallocene single- site catalysts provide several advantages, among them their chemical synthesis being much more straightforward in many cases than that of the metallocene. New non-metallocene complexes bearing ancillary ligands such as amido, alkoxo, tris(pyrazolyl)borate, diketimine and related polydentate lig- ands have appeared as a new trend in this field of research [3–7]. 1381-1169/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.molcata.2005.06.031