Thermal Pyrolysis of Polystyrene Aided by a Nitroxide End-Functionality. Experiments and Modeling
| Autor: | Almendra Ordaz-Quintero, Antonio Monroy-Alonso, Enrique Saldívar-Guerra |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Nitroxide mediated radical polymerization
Materials science thermal pyrolysis Bioengineering 02 engineering and technology 010501 environmental sciences polystyrene lcsh:Chemical technology 01 natural sciences Styrene lcsh:Chemistry chemistry.chemical_compound Chemical Engineering (miscellaneous) lcsh:TP1-1185 nitroxide mediated polymerization 0105 earth and related environmental sciences chemistry.chemical_classification Process Chemistry and Technology mathematical modeling Polymer 021001 nanoscience & nanotechnology Monomer Polymerization chemistry Chemical engineering lcsh:QD1-999 Yield (chemistry) Polystyrene 0210 nano-technology Pyrolysis |
| Zdroj: | Processes, Vol 8, Iss 432, p 432 (2020) Processes Volume 8 Issue 4 |
| ISSN: | 2227-9717 |
| Popis: | The thermal pyrolysis of polystyrene (PS) is gaining importance as the social pressure for achieving a circular economy is growing moreover, the recovery of styrene monomer in such a process is especially relevant. In this study, a simple thermal pyrolysis process in the temperature range of 390&ndash 450 ° C is developed. A working hypothesis is that by using a nitroxide-end functionalized PS (PS-T or dormant polymer), the initiation process for the production of monomer (unzipping) during the PS pyrolysis could be enhanced due to the tendency of the PS-T to activate at the nitroxide end. Two types of PS were used in this work, the first one was synthesized by free-radical polymerization (FRP-dead polymer) and the second by nitroxide-mediated polymerization (NMP) using three levels of nitroxide to initiator ratio: 1.3, 1.1, and 0.9. Analysis of the recovered products of the pyrolysis by gas-mass spectroscopy shows that the yield of styrene increases from &sim 33% in the case of dead polymer to &sim 38.5% for PS-T. A kinetic and mathematical model for the pyrolysis of dead and dormant polymer is proposed and solved by the method of moments. After a parameter sensitivity study and data fitting, the model is capable of explaining the main experimental trends observed. |
| Databáze: | OpenAIRE |
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