Synthesis of ethylene copolymers with 2-allylphenol by using half-titanocene catalysts containing SiEt3-, SiiPr3-substituted phenoxide ligands, Cp*TiCl2(O-2,6-iPr2-4-SiR3-C6H2) (R = Et, iPr)

Abstract

Ethylene copolymerisation with 2-allylphenol (AP, pretreated with AlⁱBu₃) catalysed by Cp*TiCl₂(O-2,6-ⁱPr₂-4-R-C₆H₂) (R = SiEt₃, SiⁱPr₃) gave rather high molecular weight copolymers containing a phenolic moiety (M_n = 9300–32 500 g mol⁻¹, AP up to 11.7 mol%) with uniform compositions (observed as a sole melting temperature from the DSC thermogram). The catalysts containing trialkylsilyl substituted phenoxide ligands were effective in the copolymerisation; pretreatment of AP with AlⁱBu₃ and 2,6-^tBu₂C₆H₃OH was effective for obtaining the copolymers with high catalytic activity and efficient AP incorporation.