Polyaniline supported Salen complex as highly active and recyclable catalysts for copolymerization of CO2 and epoxides

Abstract

A new heterogeneous catalyst, polyaniline (PANI) supported SalenCrⅢCl complex was investigated for the alternating copolymerization of cyclohexene oxide (CHO) with carbon dioxide (CO2) in the presence of [PPN]Cl (bis(triphenylphosphine)iminium chloride). The FT-IR, SEM/TEM, XRD, and XPS results indicated that SalenCrⅢCl was successfully supported on PANI. The resulted catalyst (SalenCrⅢCl-PANI) exhibited excellent catalytic performance for alternating copolymerization of CHO with CO2. Compared with the homogeneous SalenCrⅢCl, the heterogeneous salenCrⅢCl-PANI had obvious effect on microstructures of the copolymer, and the obtained polymer was found to be a linear alternating copolymer with narrower molecular weight distribution. The effects of various reaction parameters were also studied in detail, the reaction gives yield=12.91 gPolym./gSupp. Cat., Mn=12.21 kg/mol, Mw/Mn(PDI)=1.16 at 5.0 MPa CO2 pressure, 80 °C and 10 h. The SalenCrⅢCl-PANI maintained good catalytic activity and selectivity after reuse.