Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability
Abstract
This study provides new information on the thermal stability and kinetics of pyrolysis of commonly used resins in solid-phase peptide synthesis. Pyrolysis process of 4-benzyloxybenzyl alcohol resin was monitored by simultaneous TGA-DTG measurements in a nitrogen atmosphere, at four different heating rates (5, 10, 20 and 30 K min(-1)). Kinetic computations included the model-free (isoconversional) and model-based methods for reliable estimation of kinetic parameters and the mechanism of investigated process. Based on the findings from applied methods, the pyrolysis process can be described by three reaction steps, where one of them encompasses the consecutive reactions. The first step (n-th order reaction, referred to Fn) is attributed to the random scission of the main chain in PS (polystyrene) solid support, where polymer radicals were formed. The second step proceeds through homolytic cleavage path of ether linkage of the resin (by the first-order reaction, referred to F1) and then v...ia phenoxy radical (semiquinone) formation which is converted into the benzoquinone through a dehydrogenation (by autocatalysis reaction, referred to Cnm). Finally, the third step (referred to Fn reaction) was characterized by depolymerization mechanism, which takes place at higher temperatures (T > 385 degrees C). With determined kinetic parameters and the most probable mechanism functions, the model agrees excellently with experimental data. By applying the obtained kinetic results, isothermal life-time prediction was also performed.
Keywords:
Wang resin / Pyrolysis / Homolytic cleavage / Benzene fragments / AutocatalysisSource:
Polymer Degradation and Stability, 2021, 189Publisher:
- Elsevier Sci Ltd, Oxford
Funding / projects:
- Ministry of Science, Technological Development and Innovation of the Republic of Serbia, institutional funding - 200105 (University of Belgrade, Faculty of Mechanical Engineering) (RS-MESTD-inst-2020-200105)
DOI: 10.1016/j.polymdegradstab.2021.109606
ISSN: 0141-3910
WoS: 000677487900013
Scopus: 2-s2.0-85106255492
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Institution/Community
Mašinski fakultetTY - JOUR AU - Janković, Bojan AU - Manić, Nebojša PY - 2021 UR - https://machinery.mas.bg.ac.rs/handle/123456789/3549 AB - This study provides new information on the thermal stability and kinetics of pyrolysis of commonly used resins in solid-phase peptide synthesis. Pyrolysis process of 4-benzyloxybenzyl alcohol resin was monitored by simultaneous TGA-DTG measurements in a nitrogen atmosphere, at four different heating rates (5, 10, 20 and 30 K min(-1)). Kinetic computations included the model-free (isoconversional) and model-based methods for reliable estimation of kinetic parameters and the mechanism of investigated process. Based on the findings from applied methods, the pyrolysis process can be described by three reaction steps, where one of them encompasses the consecutive reactions. The first step (n-th order reaction, referred to Fn) is attributed to the random scission of the main chain in PS (polystyrene) solid support, where polymer radicals were formed. The second step proceeds through homolytic cleavage path of ether linkage of the resin (by the first-order reaction, referred to F1) and then via phenoxy radical (semiquinone) formation which is converted into the benzoquinone through a dehydrogenation (by autocatalysis reaction, referred to Cnm). Finally, the third step (referred to Fn reaction) was characterized by depolymerization mechanism, which takes place at higher temperatures (T > 385 degrees C). With determined kinetic parameters and the most probable mechanism functions, the model agrees excellently with experimental data. By applying the obtained kinetic results, isothermal life-time prediction was also performed. PB - Elsevier Sci Ltd, Oxford T2 - Polymer Degradation and Stability T1 - Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability VL - 189 DO - 10.1016/j.polymdegradstab.2021.109606 ER -
@article{ author = "Janković, Bojan and Manić, Nebojša", year = "2021", abstract = "This study provides new information on the thermal stability and kinetics of pyrolysis of commonly used resins in solid-phase peptide synthesis. Pyrolysis process of 4-benzyloxybenzyl alcohol resin was monitored by simultaneous TGA-DTG measurements in a nitrogen atmosphere, at four different heating rates (5, 10, 20 and 30 K min(-1)). Kinetic computations included the model-free (isoconversional) and model-based methods for reliable estimation of kinetic parameters and the mechanism of investigated process. Based on the findings from applied methods, the pyrolysis process can be described by three reaction steps, where one of them encompasses the consecutive reactions. The first step (n-th order reaction, referred to Fn) is attributed to the random scission of the main chain in PS (polystyrene) solid support, where polymer radicals were formed. The second step proceeds through homolytic cleavage path of ether linkage of the resin (by the first-order reaction, referred to F1) and then via phenoxy radical (semiquinone) formation which is converted into the benzoquinone through a dehydrogenation (by autocatalysis reaction, referred to Cnm). Finally, the third step (referred to Fn reaction) was characterized by depolymerization mechanism, which takes place at higher temperatures (T > 385 degrees C). With determined kinetic parameters and the most probable mechanism functions, the model agrees excellently with experimental data. By applying the obtained kinetic results, isothermal life-time prediction was also performed.", publisher = "Elsevier Sci Ltd, Oxford", journal = "Polymer Degradation and Stability", title = "Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability", volume = "189", doi = "10.1016/j.polymdegradstab.2021.109606" }
Janković, B.,& Manić, N.. (2021). Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability. in Polymer Degradation and Stability Elsevier Sci Ltd, Oxford., 189. https://doi.org/10.1016/j.polymdegradstab.2021.109606
Janković B, Manić N. Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability. in Polymer Degradation and Stability. 2021;189. doi:10.1016/j.polymdegradstab.2021.109606 .
Janković, Bojan, Manić, Nebojša, "Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability" in Polymer Degradation and Stability, 189 (2021), https://doi.org/10.1016/j.polymdegradstab.2021.109606 . .