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

•SalenCrIIICl-PANI complex was synthesized.•The catalyst used in copolymerization of CHO with CO2.

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.

Graphical abstractA new heterogeneous catalyst, polyaniline supported chromium (III) Schiff base complex was investigated for the alternating copolymerization of cyclohexene oxide with carbon dioxide in the presence of [PPN]Cl (bis(triphenylphosphine)iminium chloride).Figure optionsDownload full-size imageDownload as PowerPoint slide