Some analogies in the mechanical behavior of filled polymers

Abstract

synopsisThe temperature and frequency dependences of complex shear modulus and mechanical losses were studied for epoxy resin composition in the presence of different amounts of quartz and polystyrene fillers. The data obtained were analyzed by the use of the Williams-Landell-Ferry method. It was shown that in the mechanical behavior of filled polymers, except for the well-known temperature-time analogy there exist some lows connected with the presence of filler. The change in filler concentration leads to the same change in the real part of complex modulus as change in frequency (concentration-time analogy), and change in temperature is equivalent to concentration change (temperature-concentration analogy). The existence of these analogies is explained by a change in deformation conditions for polymeric matrix in the presence of different amount of filler, by the existence of surface layers of polymer at the interface with solid filler, and by peculiarities of the mechanical behavior of filler. It is also established that the thickness of surface layer which was determined from experimental data depends on temperature and has an extremum in the temperature region of the a-transition.

Relaxation and viscoelastic properties of heterogeneous polymeric compositions

“…In the reports (103,104) we have substantuated in detail the concentrationtemperature and concentration-time analogies for the description of properties of polymers filled with dispersed fillers, and proved the feasibility of plotting generalized log G' versus log co aT curves for specimens containing various quantities of the filler. The dependence log a T = f (T-Tg) furnishes some proof of the applicability of the WiUiams-Landell-Ferry method.…”

“…Therefore, it can be assumed that regular changes in the character of mechanical relaxation time spectra will occur with changes in the concentration of the filler. Since this problem has not been specially investigated, we have carried out the study of viscoelastic properties of filled polymers under dynamic loading conditions (164) with the aim of checking the hypothesis. We have studied frequency and temperature dependences of the complex shear modulus G An increase in the concentration of the quartz filler (curves 2 and 3) also results in an expansion of the spectrum and its shift toward larger periods.…”

On shift and resolution of relaxation maxima in two‐phase polymeric systems

“…For such curves the experimental data on the temperature dependence of G' and tan 6 for an epoxy polymer in the region of transition from glassy to rubberlike states were chosen. 6 These experimental dependences may be approximated as follows:…”

Structural Integrity Studies in Particulate Composites by Means of Thermal Capacity Measurements

“…It is well known [1][2][3][4][5][6][7] that the relaxation properties of polymeric composites are strongly affected by the presence of the boundary interphase. From this point of view it is very important to study the thermal behavior of polymeric composite systems and select information concerning the structure and properties of the boundary interphase and its effect on the overall viscoelastic behavior of the composite system.…”