Ethylene polymerization with FI complexes having novel phenoxy‐imine ligands: Effect of metal type and complex immobilization

Abstract

A series of bis(phenoxy‐imine) vanadium and zirconium complexes with different types of R3 substituents at the nitrogen atom, where R3 = phenyl, naphthyl, or anthryl, was synthesized and investigated in ethylene polymerization. Moreover, the catalytic performance was verified for three supported catalysts, which had been obtained by immobilization of bis[N‐(salicylidene)‐1‐naphthylaminato]M(IV) dichloride complexes (M = V, Zr, or Ti) on the magnesium carrier MgCl2(THF)2/Et2AlCl. Catalytic performance of both supported and homogeneous catalysts was verified in conjunction with methylaluminoxane (MAO) or with alkylaluminium compounds (EtnAlCl3−n, n = 1–3). The activity of FI vanadium and zirconium complexes was observed to decline for the growing size of R3, whereas the average molecular weight (MW) of the polymers was growing for larger substituent. Moreover, vanadium complexes exhibited the highest activity with EtAlCl2, whereas zirconium ones showed the best activity with MAO. All immobilized systems were most active in conjunction with MAO, and their activities were higher than those for their homogeneous counterparts, and they gave polymers with higher average MWs. That effect was in particular evident for the titanium catalyst. The vanadium complex 3 was also a good precursor for ethylene/1‐octene copolymerization; however, its immobilization reduced its potential for incorporation of a comonomer into a polyethylene chain. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Ethylene/POSS copolymerization behavior of postmetallocene catalysts and copolymer characteristics

“…) was also tested. The catalysts were chosen on the basis of our previous work within ethylene polymerization …”

“…The relatively broad molecular weight distribution of (co)polymers could be also explained by the presence of different stereoisomers of catalytic active species in (co)polymerization reactions performed using postmetallocene catalysts …”

“…Monoalkenyl(siloxy)‐ or monoalkenylsilsesquioxane derivates were obtained as described previously . Dichlorobis[ N ‐(salicylidene)‐1‐naphthylaminato]zirconium(IV), dichlorobis[ N ‐(salicylidene)‐1‐naphthylaminato]titanium(IV), dichlorobis[ N ‐(3,5‐di‐ tert ‐butylsalicylidene)‐1‐naphthylaminato]zirconium(IV), and dichloro[ N,N ′‐bis(salicylidene)propylenediamine]zirconium(IV) complexes were synthesized according to the procedures published elsewhere . Methylaluminoxane (MAO, 10 wt % solution in toluene, Sigma‐Aldrich), 1,2‐dichlorobenzene‐d4, hydrochloric acid (35–38%, Chempur), and methanol (Chempur) were used as purchased.…”

“…The catalysts were chosen on the basis of our previous work within ethylene polymerization. 17,18 Ethylene was copolymerized with iso-butyl-substituted monoalkenyl(siloxy)silsesquioxane (POSS-Si-6 and POSS-Si-10, Fig. 2) and monoalkenylsilsesquioxane comonomers (POSS-6 and POSS-10, Fig.…”

“…The highest catalytic activity in both ethylene homopolymerization and ethylene/POSS copolymerization was found for the bis(phenoxy-imine) zirconium complex (FI-ZrH) activated by MAO (Table 1, items [10][11][12][13][14][15][16][17][18], in comparison with the titanium counterpart FI-TiH (Table 1, items 1-9). This could be explained by possible partial deactivation of the Ti metal centers.…”