Formation of Elastomeric Polypropylene Promoted by Racemic Acetylacetonate Group 4 Complexes

Abstract

Treatment of racemic bis(acetylacetonato) group 4 complexes with MAO yields cationic complexes acting as active catalysts for the polymerization of propylene under high monomeric concentrations. By the appropriate choice of metal and solvent the properties of the polymer products can be tailored, allowing the formation of either elastomer to highly isotactic polypropylene.

Synthesis, characterization and catalytic activity of the complex titanium bis(dimethylmalonate)–bis(diethylamido) in the polymerization of propylene

“…These results have raised the question of the potential use of other bulky heteroallylic octahedral C 2 group 4 complexes. Inexpensive racemic bis-acetylacetonate titanium and zirconium complexes were also successfully presented in our laboratory for the polymerization of propylene [58,59]. By an appropriate choice of the metal and the solvent, the properties of the polymer could be tailored, allowing the formation of either elastomeric or highly isotactic polypropylene.…”

Olefin Polymerization with Non-metallocene Catalysts (Early Transition Metals)

“…The isopropyl amide complex (32a) showed higher activity than the cyclohexyl analogue (32b) [119], and the resultant polymer possessed high molecular weight with uniform molecular weight distribution (32a-Et 2 AlClÁEtAlCl 2 catalyst, M w = 2.29 9 10 6 , M w / M n = 3.0, ethylene 73 wt%). Vanadium(IV) complex with chelate bis(amide) ligand (34) showed higher activity than the bis(amide) analogue (33) in ethylene polymerization [activities in the presence of Et 2 AlClÁEtAlCl 2 : 213 kg-PE/mol-VÁh, 54 kg-PE/mol-VÁh for 34, 33, respectively: ethylene 1 atm in toluene at 30 8C, Al/V = 50]. Although the activity in the ethylene polymerization by 36 is close to that by 32a (178 kg-PE/mol-VÁh), 34 showed higher activity in ethylene/propylene copolymerization [120].…”

Non-Cp type homogeneous catalytic systems for olefin polymerization

“…Homoleptic vanadium complex of acetylacetonate ligand 71 can be activated by aluminum alkyl chloride for ethylene/propylene copolymerization [197] but manganese analogue of 71 shows negligible activity for ethylene polymerization [198]. Group 4 heteroleptic complexes of acetylacetonate ligand 72 are all active for propylene polymerization in the presence of MAO, producing elastomeric polypropylene [199]. g 2 -Formamidinyl Zr complex 73 was activated by [NHMe 2 Ph][B(C 6 F 5 ) 4 ] for homopolymerizations of ethylene and 1-hexene [200].…”