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RESEARCH PRODUCT

Synthesis of Ultra-High-Molecular-Weight Polyethylene

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The catalytic activity of organometallic Ti-Al complexes with donor ligands in the low-pressure polymerization of ethylene was studied. These complexes were obtained by the reaction of ethylaluminium compounds like AlEt2Cl or Al2Et3Cl3 and titanium compound of the type Ti(OR)nCl4-n (where: R = C2—C10 alkyl, C6H5, C6H4X; X — m-CH3, p-CH3, m-OCH3, p-OCH3, m-Cl, p-Cl, p-Br; n = 1—4). The optimum conditions for the synthesis of these compounds, as well as their physico-chemical properties were studied by means of EPR and polarographic methods. The effect of the type and number of OR ligands in a catalytic system on the yield of polyethylene and on its properties was examined. Ti-Al catalysts with OR ligands are more stable in comparison with a standard catalytic system (TiCl4+AlEt2Cl). Low pressure polyethylene obtained with the above ca­talysts had a particularly high molecular weight, improved mechanical properties, a higher thermal resistance and a different rheological character in comparison with the standard high-density polyethylene.