6533b7d3fe1ef96bd1260c4c
RESEARCH PRODUCT
Gamma radiation induced polymerization of vinyl monomers in dense CO2
Alessandro GaliaGiuseppe SpadaroF. ScroGiuseppe FilardoGiuseppe Caputosubject
Radiation polymerizationDispersion polymerizationDense carbon dioxideRadiationMaterials scienceBulk polymerizationSettore ING-IND/27 - Chimica Industriale E TecnologicaChemical reactionVinyl monomerSupercritical fluidchemistry.chemical_compoundMonomerchemistryPolymerizationChemical engineeringPolymer chemistryMolar mass distributionMethyl methacrylatedescription
Abstract The dispersion polymerization of methyl methacrylate in dense carbon dioxide, initiated by γ-rays, utilizing different polysiloxanes as polymeric stabilizers, was investigated. The progress of the reaction, as a function of the irradiation dose, was also studied and the occurrence of a gel effect has been detected. For comparison, the dispersion polymerization has been carried out in supercritical conditions ( T =65°C and 38 MPa) in the presence of 2,2′-azobis(isobutyronitrile) (AIBN) as initiator. High molecular weight polymer (M w > 1000 kg/mol) with narrow molecular weight distribution has been obtained both with γ-rays and AIBN. The electron scanning micrographs show that regular spherical particles (average diameter ca. 2.5 μm) with narrow particle size distribution have been obtained through the dispersion polymerization mechanism in CO 2 .
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2002-01-01 | Radiation Physics and Chemistry |