Thermal degradation kinetics of polyketone based on styrene and carbon monoxide

Copolymerization of styrene with carbon monoxide to give polyketones (PK) was carried out under homogeneous palladium catalyst and polyaniline (PANI) supported palladium(II) catalyst, respectively. The copolymers were characterized by 1H NMR, 13C NMR and GPC. The results indicated that the PK catalyzed by the supported catalyst has narrow molecular weight distribution (PDI = 1.18). For comparison purpose of thermal behaviors of PK prepared by the homogeneous and the supported catalyst, thermogravimetric (TG) analysis and derivative thermogravimetric (DTG) were conducted at different heating rates. The peak temperatures (396-402 °C) for PK prepared by the supported catalyst are higher than those (387-395 °C) of PK prepared by the homogeneous catalyst. The degradation activation energy (Ek) values were estimated by Flynn-Wall-Ozawa method and Kissinger method, respectively. The Ek values, as determined by two methods, were found to be in the range 270.72 ± 0.03-297.55 ± 0.10 kJ mol−1. Structures analysis and thermal degradation analysis revealed that the supported catalyst changed the microstructures of PK, resulting in improving thermal stability of PK.