Sensitivity Analysis of Single-Phase Isothermal Free Radical-Induced Grafting of Polyethylene
| Autor: | Marie-Françoise Reyniers, Guy Marin, Fons Schreurs, Carolina Toloza, Paul Van Steenberge, Jan Nicolaas Eddy Duchateau, Dagmar R. D'hooge, Julio C. Hernández-Ortiz |
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| Rok vydání: | 2018 |
| Předmět: |
Polymers and Plastics
Organic Chemistry 02 engineering and technology Polyethylene 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Hydrogen atom abstraction 01 natural sciences Dissociation (chemistry) Isothermal process 0104 chemical sciences Polyolefin Inorganic Chemistry Reaction rate chemistry.chemical_compound surgical procedures operative Monomer Chemical engineering chemistry Polymerization Materials Chemistry 0210 nano-technology |
| Zdroj: | Macromolecular Theory and Simulations. 27:1800036 |
| ISSN: | 1022-1344 |
| Popis: | Radical‐induced grafting of polyethylene involves many reactions such as initiator dissociation, hydrogen abstraction, graft chain initiation, graft (de)propagation, crosslinking, and homo(de)polymerization. To ensure a successful grafting, both the reaction rate and degree of grafting functionalization need to be sufficiently high, implying a design of the process conditions. In the present article, assuming isothermal conditions and a single‐phase reactive system, it is demonstrated that the grafting kinetics is influenced by the hydrogen abstraction rate coefficient, the depropagation equilibrium coefficient Keq , and the initial mass fractions of monomer, initiator, and polyolefin. It is shown that the reaction extent is a consequence of the interplay of the initial monomer mass fraction and Keq , and the average grafting length is determined by grafting “from” and “to,” with longer grafts being formed through grafting “to.” Close to equilibrium, the average graft length decreases and the crosslinking density increases provided that initiator is left. Moreover, the chain length distribution of the virgin polyolefin strongly influences the molecular arrangement of the grafting points along the polyolefin chains. This can be demonstrated from the hydrogen abstraction reaction event history of polyolefin chains. |
| Databáze: | OpenAIRE |
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