کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
673813 | 1459526 | 2013 | 7 صفحه PDF | دانلود رایگان |
The non-isothermal model-free prediction procedures used for assessment of degradation isotherms of materials and products are presented and critical analyzed. To this end, these methods were applied to the following experimental data: thermo-oxidative degradation of poly (vinyl alcohol) (PVA) and thermal degradation of high density polyethylene (HDPE). The predicted conversion vs. time curves were compared with the experimental ones obtained in quasi-isothermal conditions as well as with those calculated using the degradation mechanisms and corresponding kinetic parameters obtained by Thermokinetics software package. The errors of predictions performed by model-free and model-based procedures were evaluated. Although the used software package considers relative simple reaction schemes containing maximum six steps, the predicted conversion vs. time curves by model-based procedure exhibit lower deviations from the experimental ones than those calculated by model-free procedures. The causes of the prediction errors are discussed.
► The applicability of model-free and model-fitting predictions methods for complex processes was critically analyzed.
► The predictions of quasi-isotherms of PVA and HDPE degradations were performed.
► The causes of the prediction errors were discussed.
Journal: Thermochimica Acta - Volume 558, 20 April 2013, Pages 67–73