Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
CROSS-LINK DENSITY INFLUENCE ON THE RELAXATIONS IN GLASS-FORMING AND GEL-FORMING POLYURETHANES BY NEUTRON AND BRILLOUIN-SCATTERING
Autore:
SCHEYER Y; LEVELUT C; PELOUS J; DURAND D;
Indirizzi:
UNIV MONTPELLIER 2,LAB VERRES,PL E BATAILLON,CC 69 F-34095 MONTPELLIER FRANCE UNIV MAINE,LAB PHYSICOCHIM POLYMERES F-72017 LE MANS FRANCE
Titolo Testata:
Physical review. B, Condensed matter
fascicolo: 18, volume: 57, anno: 1998,
pagine: 11212 - 11222
SICI:
0163-1829(1998)57:18<11212:CDIOTR>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
MODE-COUPLING PREDICTIONS; ALPHA-RELAXATION; LIGHT-SCATTERING; WILLIAMS-WATTS; DYNAMICS; TRANSITION; POLYMER; POLYBUTADIENE; SPECTROSCOPY; LIQUIDS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
40
Recensione:
Indirizzi per estratti:
Citazione:
Y. Scheyer et al., "CROSS-LINK DENSITY INFLUENCE ON THE RELAXATIONS IN GLASS-FORMING AND GEL-FORMING POLYURETHANES BY NEUTRON AND BRILLOUIN-SCATTERING", Physical review. B, Condensed matter, 57(18), 1998, pp. 11212-11222

Abstract

An experimental investigation of the relaxational processes related to the glass transition is presented in a family of polymers where the cross-link density as well as the length between cross links can be varied. We used inelastic light and neutron scattering to determine the relaxation times in the 10(-8)-10(-12) s range. The relaxation time determined from neutron scattering exhibits a Q(-n) dependence, with n similar or equal to 4, and is more sensitive to variations of the cross-link density than Brillouin scattering is. However, the relaxation times measured by both techniques split from the structural relaxation determined at lower frequencies; they have a nearly Arrhenius behavior with approximately the same activation energy. The two high-frequency techniques probe the same secondary relaxation process. The dependenceon the microscopical parameters of this process suggests that the corresponding relaxing entity can be identified as a small portion of thearms of the triol.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 02/12/20 alle ore 18:19:12