6533b7d6fe1ef96bd1265b85
RESEARCH PRODUCT
Copolymerization of VDF and HFP in Supercritical Carbon Dioxide: Experimental Analysis of the Reaction Loci
Massimo MorbidelliLoredana FerroL. Ivano CostaL. Ivano CostaGiuseppe FilardoGiuseppe StortiOnofrio ScialdoneAlessandro Galiasubject
Dispersion polymerizationSupercritical carbon dioxidePolymers and PlasticsOrganic ChemistryRadical polymerizationsupercritical carbon dioxide fluoropolymers free radical polymerization polymerization kineticsSettore ING-IND/27 - Chimica Industriale E TecnologicaInorganic Chemistrychemistry.chemical_compoundchemistryPolymer chemistryCarbon dioxideMaterials ChemistryCopolymerCarboxylateHexafluoropropyleneFluoridedescription
Free radical copolymerization reactions of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) were carried out in supercritical carbon dioxide at T=50 °C. When ammonium carboxylate perfluoropolyether surfactants were used, the formation of polymer particles was observed provided that HFP mole fraction in the feed was not larger than 0.30. Under these conditions, the effect of the total interphase area of the polymer phase, Ap, on the product propertieswas investigated by comparing experiments with largely different amounts of stabilizer, i.e., ranging from precipitation (smaller Ap) to dispersion (larger Ap) polymerization systems. We found that the copolymer molecular weight distribution (MWD) is heavily affected by Ap. This experimental evidence strongly supports the presence of two reaction sites, the CO2-rich and the polymer-rich phase: the contribution of both is important in the examined range of operating conditions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-11-12 |