Thermal kinetic parameters and evolved gas analysis (TG-FTIR-MS) for thiourea-formaldehyde based polymer metal complexes

摘要

Two polymer metal complexes with a general formula of TUF-M(II) (M = Co, Cu) were synthesized by the reaction of a thiourea-formaldehyde resin (TUF) and transition metal ions. The thermal degradation of TUF-M(II) was investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) during pyrolysis and combustion. The kinetic parameters for the thermal degradation were evaluated using the Coats-Redfern and Friedman equations. An evolved gas analysis (EAG) during the thermal decomposition of TUF-M(II) was performed for the pyrolysis and combustion up to 800 C using both online coupled TG-FTIR and simultaneous TG-MS. The emissions of CS_2, NH_3, SO_2, COS, HCN, H_2NCN and HNCS were identified during the thermal degradation of TUF-M(ll). The total mass loss resulting from the pyrolysis of TUF-Cu(II) at 775 C was 73.26%, while 44.02% of the original mass was lost at 225-325 C. The activation energy for the second stage of degradation of the combustion (189.2 KJ mol~(-1), 184.5 KJmol~(-1)) was higher than that of the pyrolysis (179.8K.Jmol~(-1), 175.1 KJrnol~(-1)) at a similar stage for both complexes using the Coats-Redfern method.