Journal of Polymer Science Part B: Polymer Physics, Vol.34, No.3, 459-470, 1996
Characterization of the Molecular Deformation-Behavior of Glassy Epoxy-Resins by Rheooptical FTIR Spectroscopy
Rheo-optical FTIR spectroscopy was used for the first time to monitor molecular orientation phenomena in highly crosslinked epoxies. After studying the orientation behavior of epoxy/amine networks during uniaxial deformation above their glass transition temperature in a preceding article, this article deals with the rheo-optical characterization of the deformation process of those epoxy systems below T-g. The orientation behavior is influenced by the different molecular structure of the constituents and the free volume entrapped in the resins. Yield strain and tensile modulus are correlated with the slope of the orientation function. The orientation function was found to show an abrupt change of its slope in the yield point region. This phenomenon is discussed with respect to the mechanism of plastic deformation.
Keywords:DIGLYCIDYL ETHER EPOXIES;MECHANICAL-PROPERTIES;PLASTIC-DEFORMATION;ATACTIC POLYSTYRENE;YIELD-POINT;BISPHENOL;POLYMER;TEMPERATURE;DEPENDENCE;STRAIN