Catalysts for the Polymerization of Isoprene to trans-1,4-Polyisoprene (Synthetic Balata)

Polymerization of Butadiene with V(acac)3-Methylaluminoxane Catalyst

“…(C 5 H 4 Me)VCl 2 -MAO and CpVCl-MAO catalysts give poly(Bd) consisting of mainly cis-1,4 structure. [5] We also briefly reported that a V(acac) 3 -MAO catalyst gave poly(Bd) consisting of 64% cis-1,4 units. [6] Recently, Suzuki et al [7] reported that V(acac) 3 -MAO catalyst gave poly(Bd) consisting of 55.5% cis-1,4, 33.6% trans-1,4, and 10.9% 1,2-vinyl units.…”

“…[5] We also briefly reported that a V(acac) 3 -MAO catalyst gave poly(Bd) consisting of 64% cis-1,4 units. [6] Recently, Suzuki et al [7] reported that V(acac) 3 -MAO catalyst gave poly(Bd) consisting of 55.5% cis-1,4, 33.6% trans-1,4, and 10.9% 1,2-vinyl units. Ricci et al reported that V(acac) 3 -MAO catalyst gave predominantly trans-1,4 polymers (96%).…”

“…In polymerizations of Bd, VCl 3 , VCl 4 and VOCl 3 in combination with AlR 3 or AlR 2 Cl give trans-1,4-polymer, [2] and trans-1,4-poly(Bd) can also be synthesized by using V(acac) 3 -AlR 2 Cl and VCl 3 N 3 THF-AlR 2 Cl catalysts. [3] Syndiotactic 1,2-poly(Bd) is obtained with V(acac) 3 -AlR 3 catalyst. [4] On the other hand the polymerization of Bd with vanadium compounds in combination with MAO has been studied to produce stereoregular polymers of Bd.…”

“…[6] Recently, Suzuki et al [7] reported that V(acac) 3 -MAO catalyst gave poly(Bd) consisting of 55.5% cis-1,4, 33.6% trans-1,4, and 10.9% 1,2-vinyl units. Ricci et al reported that V(acac) 3 -MAO catalyst gave predominantly trans-1,4 polymers (96%). [8,9] We consider that this discrepancy on the microstructure of the poly(Bd) may result from the polymerization conditions.…”

Tunable regioselectivity in 1,3-butadiene polymerization by using 2,6-bis(dimethyl-2-oxazolin-2-yl)pyridine incorporated transition metal (Cr, Fe and Co) catalysts

“…Industry applied systems such as tianium tetraethoxides/AlEt 3 [6], vandium trichloride/AlR 3 [7][8], Co(acac) 3 /CS 2 or Ph 3 P [9-10] and recently emerged rare earth catalysts [11,12] are notable for their unique catalytic properties, in particular, polymers with high level of regioregularity such as trans-1,4 [11][12][13], cis-1,4 [14][15][16][17][18][19][20][21][22][23] and 3,4 (1,2) [24][25] regio-and/or stereoselectivity, as such, 1,2-syndiotactic [23] for polybutadiene, and syndiotactic 3,4 (1,2) [24], isotactic 3,4 [25] for polyisoprene as well as their block combinations have been unprecedently achieved.…”