SalenCr Catalyst Immobilized on Amino-Functionalized Cellulose for the Copolymerization of SO.sub.2 with Cyclohexene Oxide

In this work, by loading a chromium Salen complex on amino-functionalized cellulose (AFC-SalenCr), a novel and efficient heterogeneous catalyst was successfully synthesized, and used for the copolymerization of sulfur dioxide (SO.sub.2) with cyclohexene oxide for the first time. The catalysts were characterized by FTIR, XPS, ICP-MS and TGA for their physiochemical and thermal properties. The as-prepared AFC-SalenCr showed high catalytic activity for the copolymerization. Under optimal reaction conditions, the molecular weight of the resultant copolymer could reach 40,100 g/mol. Moreover, the catalyst was able to recover facilely and be reused for four cycles without any significant activity loss. In addition, the thermal degradation kinetics of the synthesized copolymer was further studied using Kissinger and Flynn-Wall-Ozawa methods for the first time, which indicated that the activation energy of the thermal degradation was 92.8 kJ/mol and 94.0 kJ/mol, respectively.