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RESEARCH PRODUCT
The rate of polymerization in two loci reaction systems: VDF-HFP precipitation copolymerization in supercritical carbon dioxide
Giuseppe FilardoAlessandro GaliaGiuseppe StortiGiuseppe StortiLiborio Ivano CostaMassimo MorbidelliMassimo Morbidellisubject
Materials sciencePolymers and PlasticsRich phaseChemical kineticsReaction ratechemistry.chemical_compoundSupercritical carbon dioxideCopolymerCopolymerizationPhase (matter)Single phasePolymer chemistryMaterials ChemistryCopolymerHeterogeneous conditionPolymerRate of polymerizationReaction systemchemistry.chemical_classificationSupercritical carbon dioxideHexafluoropropyleneExperimental investigationComparative simulationGeneral ChemistryPolymerComputer simulationReaction rates Supercritical fluid extractionReactant concentrationchemistryPolymerizationChemical engineeringReaction conditionVinylidene fluoride Carbon dioxideHeterogeneous polymerizationHexafluoropropylenePolymer phasedescription
When the copolymerization of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) is carried out in supercritical carbon dioxide (scCO 2) under heterogeneous conditions, the reaction occurs both in the continuous CO 2-rich phase and in the dispersed polymer-rich phase. The two phases being characterized by different values of reactant concentrations and kinetic parameters, one would expect that the reaction kinetics is affected by the polymer phase holdup in the reactor. However, the reaction rate is almost insensitive to the amount of produced polymer, at least at specific reaction conditions. This apparent contradiction is discussed and clarified in this paper by a series of comparative simulations carried out using different models, accounting for the reaction in one single phase (one-locus) or in two phases (two-loci). This analysis provides general procedures which can be used to design experimental investigations able to identify the number of reaction loci for a given heterogeneous polymerization system. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2011-10-01 | Polymer Engineering & Science |