Effect of interfacial area on heterogeneous free radical grafting of vinyl monomers in supercritical carbon dioxide: Grafting of acrylic acid on poly(vinylidenefluoride) nanoparticles
- Authors: Lanzalaco, S.; Scialdone, O.; Galia, A.
- Publication year: 2015
- Type: Articolo in rivista (Articolo in rivista)
- Key words: biomedical applications; functionalization of polymers; grafting; radical polymerization; synthesis and processing; Materials Chemistry2506 Metals and Alloys; Polymers and Plastics; Surfaces, Coatings and Films; Chemistry (all)
- OA Link: http://hdl.handle.net/10447/231952
Abstract
The role of the polymer interfacial area on free radical grafting of acrylic acid (AA) onto poly(vinylidenefluoride) (PVDF) was studied at 65°C using supercritical carbon dioxide (scCO2) as a solvent and swelling agent, benzoylperoxide (BPO) as chemical initiator and PVDF nanoparticles as polymer matrix. Under adopted conditions PVDF particles do not melt neither dissolve in the reaction medium and FTIR analyses performed on carefully washed nanoparticles confirmed the achievement of high grafting levels. The mass fraction of grafted AA increased with the grafting time and the BPO concentration while it decreased when the density of the fluid phase was enhanced. Collected results suggest that the grafting level obtained by free radical grafting of vinyl monomers onto solid polymer in scCO2 can be significantly enhanced by increasing the interfacial area of the matrix.