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Prepreg aging in relation to tack
Author(s) -
Ahn K. J.,
Peterson L.,
Seferis J. C.,
Nowacki D.,
Zachmann H. G.
Publication year - 1992
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1992.070450304
Subject(s) - thermosetting polymer , materials science , composite material , isothermal process , epoxy , glass transition , carbon fibers , activation energy , polymer , composite number , thermodynamics , chemistry , physics , organic chemistry
Thermoanalytical measurements and tack tests were both performed using a commercially available carbon fiber/epoxy prepreg system (Hercules 3501–6) to examine changes caused by aging as they affect handling and processability of thermosetting matrix‐based composites. Combining these techniques, a relationship between prepreg bulk and surface characteristics in relation to aging was investigated. Isothermal kinetic studies at low temperatures showed maximum conversions (α m ) that increased with increasing cure temperatures. In addition, a linear relationship between glass transition temperatures ( T g ) and conversions (α) was observed regardless of aging (or cure) temperatures. Energy of separation of prepreg stacks, which may be viewed as a measure of prepreg tack, showed a maximum value at a specific temperature. The maximum energy of separation was observed in the temperature range of 20–25°C above the glass transition temperature for a given sample. However, the maximum energy of separation values decreased with increasing aging times (or conversions), implying that prepreg tack was a viscoelastic property rather than a viscous property of the resin matrix in the prepreg.