Premium
A methodology for characterizing reactive coatings: Time–temperature–transformation (TTT) analysis of the competition between cure, evaporation, and thermal degradation for an epoxy‐phenolic system
Author(s) -
Gan S.,
Gillham J. K.,
Prime R. B.
Publication year - 1989
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.1989.070370316
Subject(s) - thermosetting polymer , glass transition , materials science , epoxy , isothermal process , vitrification , degradation (telecommunications) , composite material , evaporation , thermal , polymer , chemical engineering , thermodynamics , medicine , telecommunications , physics , computer science , andrology , engineering
A methodology, in terms of a macroscopic isothermal time–temperature–transformation (TTT) diagram, is presented for characterizing the changes that occur isothermally in a reactive thermosetting system in which evaporation, cure, and thermal degradation occur. Iso‐weight loss contours show the progress of the loss of volatile material (mostly solvent). The gelation contour corresponds to the macroscopic viscosity rising to a definite level. The vitrification contour corresponds to the glass transition temperature ( T g ) rising to the temperature of cure ( T cure ). Iso‐ T g contours show the progress of cure in terms of the easily measured T g (rather than chemical conversion). The iso‐ T g contours also show the influence of thermal degradation competing with cure. Degradation is responsible for difficulties in assigning the glass transition temperature of the fully cured material (i.e., T g ∞ ).