III International Conference

PP-II-68EFFECT OF THE LIGAND SUBSTITUENTS IN PHENOXY-IMINE-TiCl 2COMPLEXES UPON THEIR CATALYTIC ACTIVITY IN ETHYLENEPOLYMERIZATIONMalinskaya M.Ju., Sviridova E.V., Khaikin S.Ya., Myakin S.V.St-Petersburg Department of the Boreskov Institute of Catalysis SB RAS, St-Petersburg, RussiaE-mail: ivanchev@SM2270.spb.eduThe effect of substituents at imine nitrogen and in the ortho-position of the phenoxygroup in the ligands of 6 bis(phenoxy-imine)titanium dichloride complexes upon theirNR 1 O2R 3 R 2TiCl 2(1) R 1 = C 6 H 5 , R 2 = t-Bu, R 3 = t-Bu,(2) R 1 = C 6 H 11 , R 2 = t-Bu, R 3 = = t-Bu ,(3) R 1 = C 6 H 5 , R 2 = t-Bu ,R 3 = Me,(4) R 1 = C 6 H 11 , R 2 = t-Bu, R 3 = Me,(5) R 1 = C 6 H 5 , R 2 = cumyl, R 3 = Me,(6) R 1 = C 6 H 11 , R 2 = cumyl, R 3 = Meethylene polymerization behavior is studied. The polymerization was carried out using thecatalyst in amount ~1-2 μmol and methylalumoxane (MAO) cocatalyst at ethylene pressure0.3 MPa, temperatures from 30 to 70 °С and Al:Ti molar ratio 250-500. For all catalystsystems ethylene polymerization kinetics was studied within at least 60 min.For complexes (1)-(4) containing small substituents R 2 = t-Bu and R 3 = Ме thepolymerization kinetics is found to be predominantly determined by the nature of the cyclicsubstituent R 1 at the imine nitrogen. The structure of this substituent can affect thetemperature range of the maximum catalyst activity.However, for the complexes (5) and (6) bearing a bulky substituent in the ortho-positionof the phenoxy group (R 2 = cumyl) the cyclic substituent at the imine nitrogen R 1 does notaffect the polymerization kinetics.Molecular, structural and thermal properties of the obtained polyethylenes arecharacterized.The analysis of obtained data suggests the conclusions regarding a combined effect of thesubstituents in the phenoxy groups and imine nitrogen upon the optimum temperature rangeof bis(phenoxy-imine)titanium based catalyst performances and their activity at ethylenepolymerization.289