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Titolo:
EXAMINATION OF THE FREE-VOLUME ELEMENTS I N POLYMERIC SYSTEMS BY POSITRON-ANNIHILATION SPECTROSCOPY
Autore:
SHANTAROVICH VP; YAMPOLSKII YP; KEVDINA IB; AZAMATOVA ZK; KHOTIMSKII VS;
Indirizzi:
RUSSIAN ACAD SCI,NN SEMENOV CHEM PHYS INST,UL KOSYGINA 4 MOSCOW 117977 RUSSIA RUSSIAN ACAD SCI,AV TOPCHIEV PETROCHEM SYNTH INST MOSCOW 117912 RUSSIA
Titolo Testata:
Vysokomolekularnye soedinenia. Seria A
fascicolo: 3, volume: 39, anno: 1997,
pagine: 445 - 450
SICI:
0507-5475(1997)39:3<445:EOTFEI>2.0.ZU;2-Q
Fonte:
ISI
Lingua:
RUS
Soggetto:
DISTRIBUTIONS; DEPENDENCE; LIFETIME;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
15
Recensione:
Indirizzi per estratti:
Citazione:
V.P. Shantarovich et al., "EXAMINATION OF THE FREE-VOLUME ELEMENTS I N POLYMERIC SYSTEMS BY POSITRON-ANNIHILATION SPECTROSCOPY", Vysokomolekularnye soedinenia. Seria A, 39(3), 1997, pp. 445-450

Abstract

Two ternary ethylene-propylene-norbornene copolymers, the polymers with high free volume [poly(trimethylsilyl propyne), and the perfluorodioxol-terrafluoroethylene] copolymer were studied using positron annihilation lifetime spectroscopy, Characteristics of positron annihilationlifetime spectra (I-i, tau(i)) were calculated using the PATFIT computer program, and their dependence on the number and size of defects (free-volume holes) in polymers was considered. Analysis of the kineticsof diffusion and trapping of positrons and positronium in defects shows that the number of defects is not proportional to the intensities of the corresponding components in the lifetime spectrum and depends, in particular, on the ratio between the positronium annihilation rate in the defect and the annihilation rate of nonlocalized positrons, Thisactor should be taken into account in lire qualitative estimates based on the positron annihilation lifetime measurements, which allow one to reveal the role of defects with different sizes in variations of physicochemical properties of the materials.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 16/07/20 alle ore 05:52:46