Effect of Metal Fillers on Relaxation Processes in Elastomers

Abstract

The anelasticity regions in elastic latex polymers are established by using dynamic mechanical analysis for both filler-free samples and samples filled with iron and zinc powders. Internal friction spectra show that the α-relaxation process is less intensive in the filled polymers, and the peak corresponding to the glass transition temperature shifts into the region of positive temperatures. In the case of iron powder, we establish the presence of the β-relaxation process related to the segmental mobility of macrochains in elastic polymers. For the highly elastic polymer, the β-relaxation process is found even in the filler-free system, while in the filled system it is shifted into the range of positive temperatures. The internal friction spectra correlate with the variations of frequency with temperature that are used to establish anelasticity regions, suggesting that filling results in the narrowing of this region. This effect is due to the breaking of intermolecular bonds within the polymer and the formation of new relaxation structures in the presence of fillers. At negative temperatures, the spectra feature μ-relaxation processes, which are more pronounced in the filled systems and are consequent to the formation of different forms of ice upon freezing the latex polymer.