Thermal Stability and Thermal Degradation Reaction Kinetics of 4,4'-Diphenylmethane Diisocyanatetrimer

New thermal study of polymerization and degradation kinetics of methylene diphenyl diisocyanate

“…It is observed in TG curve for MDI monomer (Fig. 2a) that monomer was thermal stable until 180.0°C, and this temperature is higher than the temperatures found in literature: 120 and 150°C [11,12]. This difference is attributed to different equipments and analyzes conditions.…”

“…Reference [12] showed the activation energy of MDI polymerization, and although less detailed than Ref [11], the average E a value found was more consistent with the polymerization process (200.99 kJ mol -1 ). The author also found the activation energy of the MDI degradation process (259.94 kJ mol -1 ).…”

“…This kinetic approach is very important, due to its possible correlation between the activation energy in the conversion degree of the reaction or the extent of the reaction (polymerization). In the literature, two papers reported the non-isothermal kinetics studies of MDI polymerization process and final polymer degradation process [11,12]; however, both did not follow the ICTAC Kinetics Committee [13]. Thus, the present paper followed these recommendations and obtained new kinetics data for both process (polymerization and degradation).…”

“…This is a diffusional method [4,22] and is in agreement with the E a vs a dependence obtained by Friedman method. The Ref [11,12] shows that just the coefficient correlation (R 2 ) value is not enough to choose a better solution. The Ftest was considered, which gives just one ideal solution, in this study (An) [15,23].…”

“…The observed polymerization process is related to the complex degradation process that generates several products, as mentioned by the Ref. [12]. The activation energy values varied more than 20-30%; therefore, the nonlinear regression was used to determine the best model.…”