SMALL DEFORMATIONS OF CROSS-LINKED POLYMERS AND COMPOSITES - SPECTRA OF STRAIN RATES

We studied the dependence of relaxation spectra of epoxy and polyester resins on with the composition of the polymer, on the size of filler particles, and on the degree of cross-linking. Relaxation transitions are detected by plotting the temperature dependences of small deformations (deformation spectra). This method, which is based on precision interferometric measurement of the creep rate, provides high resolution. The complex structure of resins and resin-based composites gives rise to a large number of relaxation regions in the deformation spectra. The effect of composite parameters (component ratio, filler dispersion, and degree of hardening) on characteristics of deformation spectra (positions and heights of peaks) are guite different for different relaxation regions A comparison of the spectra of composites allows one to predict changes in the strength characteristics in various relaxation regions and to determine critical temperature ranges.