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Titolo:
Isothermal curing by dynamic mechanical analysis of three epoxy resin systems: Gelation and vitrification
Autore:
Lopez, J; Ramirez, C; Torres, A; Abad, MJ; Barral, L; Cano, J; Diez, FJ;
Indirizzi:
Univ A Coruna, Dept Fis, EUP Ferrol, Ferrol 15405, Spain Univ A Coruna Ferrol Spain 15405 pt Fis, EUP Ferrol, Ferrol 15405, Spain
Titolo Testata:
JOURNAL OF APPLIED POLYMER SCIENCE
fascicolo: 1, volume: 83, anno: 2002,
pagine: 78 - 85
SICI:
0021-8995(20020103)83:1<78:ICBDMA>2.0.ZU;2-2
Fonte:
ISI
Lingua:
ENG
Soggetto:
NOVOLAC GLYCIDYL ETHER; TETRAGLYCIDYL-4,4'-DIAMINODIPHENYLMETHANE TGDDM; CURE KINETICS; GEL POINT; BLENDS; DDS;
Keywords:
gelation; curing of polymers;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Engineering, Computing & Technology
Citazioni:
21
Recensione:
Indirizzi per estratti:
Indirizzo: Barral, L Univ A Coruna, Dept Fis, EUP Ferrol, Avda 19 Febrero S-N, Ferrol15405, Spain Univ A Coruna Avda 19 Febrero S-N Ferrol Spain 15405 405, Spain
Citazione:
J. Lopez et al., "Isothermal curing by dynamic mechanical analysis of three epoxy resin systems: Gelation and vitrification", J APPL POLY, 83(1), 2002, pp. 78-85

Abstract

Times to gelation (t(gel)) and times to vitrification (t(vit)) during isothermal curing for the epoxy systems diglycidyl ether of bisphenol A (DGEBA)/1,3-bisaminomethylcyclohexane (1,3-BAC), tetraglycidyl-4,4'-diaminodiphenylmethane (TGDDM)/4-4'-diaminodiphenylsulfone (DDS), and TGDDM/epoxy novolac(EPN)/DDS were measured at different curing temperatures. This article reports on a method to determine t(gel) and t(vit) by dynamic mechanical analysis (DMA). Gelation was determined at the onset of the storage modulus or by the peak of the loss factor. Vitrification was defined as the curve of the storage modulus as the curve reached a constant level (endset) in DMA tests. The experimental values obtained for t(gel) and t(vit) were compared with values obtained by other experimental methods and with theoretical values (t(gel)'s) or indirect determinations (t(vit)'s). From kinetic analysis by differential scanning calorimetry, conversions corresponding to gelation were obtained for the three systems; this yielded a constant value for eachsystem that was higher than theoretical value. Values of the apparent activation energies of the DGEBA/1,3-BAC, TGDDM/DDS, and TGDDM/EPN/DDS epoxy systems were obtained from plots of t(gel)'s against reciprocal temperatures. They were 53.2, 58.2, and 46.5 kJ/mol, respectively. (C) 2002 John Wiley &Sons, Inc.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/06/20 alle ore 01:43:11