|
| << vorige | volgende >> |
Tijdschrift beschrijving
Alle jaargangen van het bijbehorende tijdschrift
Alle afleveringen van het bijbehorende jaargang
Alle artikelen van de bijbehorende aflevering
Details van artikel 3 van 8 gevonden artikelen
| Titel: |
PHOTOPOLYMERIZATION OF "DUAL-SETTING" α-TRICALCIUM PHOSPHATE CEMENTS |
| Auteur: |
Davidenko, Natalia Carrodegua, Raul Garcia Munoz, Roberto Sastre Barrio, Julio San Roman del |
| Verschenen in: |
International journal of polymeric materials |
| Paginering: | Jaargang 51 (2002) nr. 7 pagina's 577-589 |
| Jaar: |
2002-07 |
| Inhoud: |
Photo-cured "dual setting" cements based on α-tricalcium phosphate ( α-TCP) as Solid Component, S, and a mixture of water soluble acrylic monomers as Liquid Component, L, were prepared. The monomers employed were acrylamide (AA), 20 wt./vol. % and N,N'-methylenebisacrylamide (MBAA) 0.4 wt./vol. %, both dissolved in a 2.5 wt./vol. % Na 2 HPO 4 aqueous solution. Polymerization of these systems was initiated photochemically under the action of visible light (wavelength in excess of 400 nm) and using camphorquinone as photoiniator. During the kinetic study of the photopolymerization of L it was found that the amide groups present in the monomer structures acted as co-initiator, and efficiently photo-reduced the camphorquinone. The addition of N,N-dimethyl aminobenzyl alcohol (DMOH) as co-initiator produced a retarding effect on the polymerization. This phenomenon was explained in terms of chain transfer. It was also found that the photo-cured mechanism of L does not obey a simple free radical polymerization scheme since it does not fit in with the well known kinetic expression for "ideal" photo-initiated polymerization. The kinetic study of the photopolymerization of cements was carried out at different irradiation intensities (from 0.70 to 1.37 mcal/s) and varying the filler content from 47.6 to 71.4 wt.-%. It was established that the photopolymerization rate rises linearly with the L/S ratio used. This result was satisfactoy explained on the basis of the Mesophase Theory. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 3 van 8 gevonden artikelen
| << vorige | volgende >> |