ABSTRACT
The article investigates into the type of distributions of relaxing and delay particles over their relaxation and delay times built upon the mathematical models of relaxation and creep of polymeric materials. The relaxation and delay times characterise the transition times of relaxing or delay particles from one stable energy state to another (Makarov et al., 2016).
The nature of such transitions can be different. It depends on both the rheology of a polymer material and the applied deformation or load value. It can be explained, on the one hand, by conformational energy transfers within the macromolecules of material when their shape changes during rearrangement, and on the other hand, there are shears of macromolecules and other changes caused by energy (Makarov et al., 2015a). The most satisfactory results considering the processes of deformation of polymeric materials can be obtained using rather complex models such as a consequent combination of a number of the Maxwell and the Kelvin-Voigt models (Pereborova et al., 2020a). The application of modelling for an accurate quantitative description of deformation or relaxation in the study of the properties of polymers encounters certain difficulties (Pereborova et al., 2020b). Different operational behaviour of polymers, structural changes during deformation depending on the sample background, temperature, duration of action, and stress-strain values, make it difficult to obtain the exact rheological characteristics of the process (Pereborova et al., 2020c). However, the relevance of modelling for a qualitative or approximate quantitative description of mechanical properties is obvious.
