Preparation of tethered half-titanocene complex on cross-linked polystyrene beads for using in syndiospecific polymerization of styrene

In this work the cross-linked polystyrene beads were functionalized with silyl hydride groups. Two synthetic procedures were employed to tether of indenyltrichlorotitanium (IndTiCl3) on the functionalized polystyrene beads. In one approach (method A), the half-titanocene catalyst bearing an allyl group (1-allylindenyltrichlorotitanium) was synthesized and covalently anchored on the functionalized polystyrene by using of hydrosilylation chemistry. In the second approach (method B), the half-titanocene complex was synthesized on the functionalized polystyrene beads. The polymer-supported catalysts were tested for styrene polymerization using methylaluminoxane (MAO) as a cocatalyst. The obtained results revealed that the supported catalyst prepared with method (A) has higher catalytic activity and syndiotacticity than the supported catalyst obtained by method (B). In addition the scanning electron microscopy (SEM) images showed that the polymer particle replicates the shape of the carrier. Furthermore, the 13C NMR and differential scanning calorimetry (DSC) studies confirmed the high syndiotacticity of obtained polymers.

Tethering a catalytic complex on support was employed in the immobilization of 1-allylindenyltrichlorotitanium on silyl hydride functionalized polystyrene beads. This polymer-supported catalyst was employed in styrene polymerization using MAO as a cocatalyst. Results showed that the supported catalyst displays a high activity toward the formation of syndiotactic polystyrene with a high syndiotacticity.Figure optionsDownload high-quality image (50 K)Download as PowerPoint slide