Preparation of high 1,2‐orientation butadiene‐styrene copolymer by coordination copolymerization with molybdenum‐based catalytic system

Abstract

In this study, with Mo-based catalytic systems consisting of molybdenum pentachloride (MoCl 5 ) as the main catalyst, alkyl aluminum as the cocatalyst and organophosphorus compound as the ligand, high 1,2-orientation butadiene (Bd)-styrene (St) copolymers were prepared by the coordination polymerization. The effects of phosphorous ligand, alkyl aluminum, polymerization temperature, polymerization time and monomers feed ratios on the monomer conversion and intrinsic viscosity of copolymers were explored in detail. The experimental results indicated that with MoCl 5 •TBP (tributyl phosphate)/Al(OPhCH 3 )(i-Bu) 2 as the catalytic system to initiate Bd-St copolymerization, the reactivity ratios of butadiene and styrene monomers are 3.64 and 0.16, and the 1,2-structural content in the resulting copolymers is over 80%, regarded as high 1,2-orientation Bd-St copolymers. All these results provided a basis for the design of catalyst used to prepare high 1,2-orientation Bd-St rubber.

Degradation of Polydienes Induced by Alkyllithium: Characterization and Reaction Mechanism

“…The microstructure of the samples was characterized by 1 H NMR, showing that cis-PB contained 97% 1,4-cis, 2% 1,4-trans, and 1% 1,2-vinyl units, while HVPB contained 86% 1,2vinyl units and 14% 1,4-trans units. PI 34 and PS 35 were synthesized according to published methods. FTIR and NMR ( 1 H and 13 C) spectra for all polymers listed above are provided in the Supporting Information.…”