Objemová a entalpická relaxace a-PMMA, PC a a-SE, vyhodnocení relaxačního objemového modulu

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F04%3A63502365" target="_blank" >RIV/70883521:28110/04:63502365 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985874:_____/04:00104387

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

Enthalpy and Volume Relaxation of PMMA, PC and a-Se; Evaluation of Aging Bulk Moduli.

Popis výsledku v původním jazyce

Enthalpy, h, and volume, v, relaxation (physical aging) of poly(methyl methacrylate), PMMA, and polycarbonate, PC, were measured using Differential Scanning Calorimetry and mercury-in-glass dilatometry. For PMMA both temperature down-jumps and up-jumps were studied. Attention was paid to the influence of cooling/heating rates on aging process with the result that it is related to the corresponding shift of glass transition temperature, Tg. From the time dependence of enthalpy, h, and volume, v, the aging modulus was defined as Ka = (?h/?v)T, and was found to be ca 2 GPa. This corresponds roughly to the inverse value of the compressibility, ?l, in the vicinity of Tg. The results of the measurements on amorphous selenium supported the notion that Ka assumes values close to 1/?l. The measured Ka values were about 5 GPa, in fair agreement with compressibility data extracted from pvT measurements.

Název v anglickém jazyce

Enthalpy and Volume Relaxation of PMMA, PC and a-Se; Evaluation of Aging Bulk Moduli.

Popis výsledku anglicky

Enthalpy, h, and volume, v, relaxation (physical aging) of poly(methyl methacrylate), PMMA, and polycarbonate, PC, were measured using Differential Scanning Calorimetry and mercury-in-glass dilatometry. For PMMA both temperature down-jumps and up-jumps were studied. Attention was paid to the influence of cooling/heating rates on aging process with the result that it is related to the corresponding shift of glass transition temperature, Tg. From the time dependence of enthalpy, h, and volume, v, the aging modulus was defined as Ka = (?h/?v)T, and was found to be ca 2 GPa. This corresponds roughly to the inverse value of the compressibility, ?l, in the vicinity of Tg. The results of the measurements on amorphous selenium supported the notion that Ka assumes values close to 1/?l. The measured Ka values were about 5 GPa, in fair agreement with compressibility data extracted from pvT measurements.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BJ - Termodynamika

OECD FORD obor

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Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2004

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Non - Crystaline Solids

ISSN

0022-3093

e-ISSN

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Svazek periodika

344

Číslo periodika v rámci svazku

31

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

148-157

Kód UT WoS článku

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EID výsledku v databázi Scopus

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