A new catalytic system for copolymerization of styrene with CO:PdCl 2/bipy/M(CF 3SO 3) n

Abstract

A new three-component catalytic system, PdCl 2/bipy/M(CF 3SO 3) n , was studied for copolymerization of styrene with CO to prepare alternating polyketone (PK). It is found that the PdCl 2/bipy/CF 3SO 3H catalytic system had a very low catalytic activity for copolymerization of CO with styrene, but when M(CF 3SO 3) n was introduced instead of CF 3SO 3H, the PdCl 2/bipy/M(CF 3SO 3) n catalytic system exhibited high activity. The copolymer was characterized by elemental analysis, FTIR, 1H NMR, DSC and TGA. The results indicated that the copolymer is a linear alternating copolymer of carbon monoxide and styrene with glass transition temperature, melting point, and decomposition temperature of 275, 350, and 400 °C, respectively. The effects of M(CF 3SO 3) n , ligands, p-benzoquinone/PdCl 2 ratio, solvents, and reaction temperatures on the reaction have been discussed in detail. The results showed that this novel catalytic system exhibited high activity, especially when Cu(CF 3SO 3) 2 was used. The corresponding productivity was 20,000 gPK/molPd h when the reaction was carried out at 338 K for 4 h under 3.0 MPa of CO.