Ethylene-co-norbornene polymers [P(E-co-N)s] have been synthesized with the dicarbollide catalysts (η5-C2B9H11)M (NHEt2) [M = Ti (1), Zr (2)] activated with methlaluminoxane (MAO) or alkylaluminium compounds, as AlMe3 (TMA), Al(Bu)3 (TIBA), AlH(Bu)2 (DIBALH), AlEt2Cl (DEAC). Polymerization results by 1-TIBA, 2-TIBA, 1-MAO and 2-MAO catalysts have been preliminary compared with those of cyclopentadienyl derivatives of the group 4 metals, (η5-C5R5)TiX3 [R = H, X = Cl (3); R = Me, X = Cl (4), Me(5)], (η5-C5H5)ZrCl3 (6), ethylenebis(1-indenyl) zirconium dichloride (7) and "Cp-free" compuonds M(NEt2)4 [M = Ti (8), Zr (9)] precursors of the dicarbollide compounds 1-2, under the same conditions (Tp = 50°C, [M] = 1 × 10-3M; Pr = 1 atm; [N] = 1.75M). The 1-TIBA catalysts exhibit productivity values greater than the corresponding MAO activated system and incorporate high concentration of the cyclic monomer in the copolymer products (N mol-% = 38-45). Crystalline blocks of isotactic alternating NENE sequences were identified in the P(E)-co-N)s copolymers produced by these catalysts by means of 13C NMR and DSC analysis. The dicarbollide derivatives 1 and 2 were also efficiently activated with the alkyl aluminium compounds TMA, DIBALH and DEAC at very low A1/M molar ratio (A1/M = 10); the titanium and zirconium cyclopentadienyl derivatives 3,4,6,7 are inactive under these conditions.

Syhtesis of etylene-co-norbornene polymers promoted by MAO free catalysts based on group IV dicarbollide complexes

GRASSI, Alfonso;MILIONE, Stefano;
2001

Abstract

Ethylene-co-norbornene polymers [P(E-co-N)s] have been synthesized with the dicarbollide catalysts (η5-C2B9H11)M (NHEt2) [M = Ti (1), Zr (2)] activated with methlaluminoxane (MAO) or alkylaluminium compounds, as AlMe3 (TMA), Al(Bu)3 (TIBA), AlH(Bu)2 (DIBALH), AlEt2Cl (DEAC). Polymerization results by 1-TIBA, 2-TIBA, 1-MAO and 2-MAO catalysts have been preliminary compared with those of cyclopentadienyl derivatives of the group 4 metals, (η5-C5R5)TiX3 [R = H, X = Cl (3); R = Me, X = Cl (4), Me(5)], (η5-C5H5)ZrCl3 (6), ethylenebis(1-indenyl) zirconium dichloride (7) and "Cp-free" compuonds M(NEt2)4 [M = Ti (8), Zr (9)] precursors of the dicarbollide compounds 1-2, under the same conditions (Tp = 50°C, [M] = 1 × 10-3M; Pr = 1 atm; [N] = 1.75M). The 1-TIBA catalysts exhibit productivity values greater than the corresponding MAO activated system and incorporate high concentration of the cyclic monomer in the copolymer products (N mol-% = 38-45). Crystalline blocks of isotactic alternating NENE sequences were identified in the P(E)-co-N)s copolymers produced by these catalysts by means of 13C NMR and DSC analysis. The dicarbollide derivatives 1 and 2 were also efficiently activated with the alkyl aluminium compounds TMA, DIBALH and DEAC at very low A1/M molar ratio (A1/M = 10); the titanium and zirconium cyclopentadienyl derivatives 3,4,6,7 are inactive under these conditions.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11386/1003156
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