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Separation of gelation from vitrification in curing of a fiber‐reinforced epoxy composite
Author(s) -
Bilyeu Bryan,
Brostow Witold,
Menard Kevin P.
Publication year - 2002
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.10505
Subject(s) - materials science , vitrification , epoxy , glass transition , curing (chemistry) , composite material , differential scanning calorimetry , composite number , dynamic mechanical analysis , polymer , thermodynamics , medicine , physics , andrology
Prepregs of a mixture of the tetrafunctional epoxy tetraglycidyl 4,4‐diaminodiphenyl methane (TGDDM) and the tetrafunctional amine 4,4'‐diaminodiphenylsulfone (DDS) were characterized with temperature‐modulated DSC (TMDSC) as well as dynamic mechanical analysis (DMA). The baseline shift of the glass transition was separated from the curing exotherm by using temperature‐modulated and step scan DSC temperature scans. Likewise, the baseline shift in heat capacity due to vitrification was isolated using TMDSC isotherms. Using the TMDSC glass transition temperature, degree of conversion, and vitrification results, combined with the gelation data generated from DMA, a time‐temperature‐transformation (TTT) diagram was constructed, providing information necessary for optimization of industrial processing of the epoxy prepreg. Thus, effects of storage, preprocessing, and postprocessing on the overall curing process are taken into account.