PSI - Issue 40

S.N. Danilova et al. / Procedia Structural Integrity 40 (2022) 118–123 S.N. Danilova, A.A. Dyakonov, A.P. Vasilev, A.A. Okhlopkova / Structural Integrity Procedia 00 (2022) 000 – 000

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The primary factor of changing the mechanical parameters of PCM is the formation of the ordered supramolecular structure. It is known that the change of the polymer structural organization depends on the shape, size, composition and state of the surface in the particles being introduced (Samuels (1967)). In order to find out the influence of the basalt fiber on the processes of the UHMWPE structure formation, the structure of PCM was examined using the method of scanning electron microscopy (SEM) (Fig.1). The structure of the original UHMWPE is characterized as spherulitic. When BF is introduced, there occurs transformation of the structure into an unordered one, which is associated with the increase of the UHMWPE rate of crystallization on the surface of the fibers. As this takes place, it can be seen that basalt fiber is distributed chaotically within the polymer matrix. In case of preliminarily mechanically activated composites, preservation of the UHMWPE spherulitic structure can be observed. It was found out that the increase of the mechanical co-activation time of the UHMWPE and BF results in decreasing the size of spherulites and decrease in the length of the fibers (Fig. 1 c and d). Decrease in the size of the spherulite is possibly attributable to the increase in the mobility of the macromolecules, i.e. short fibers do not interfere with the processes of the PCM structure formation. It is known that the formation of the spherulitic structure of PCM contributes to the increase in hardness and bearing capacity of the material (Panin et al. (2017)). Thus, the results of research with the use of the electron microscopy conform to the physical and mechanical studies of PCM.

Fig. 2. Microphotographs of the etched structure of the composites containing 2 wt.% BF (magnification х 150): a – original UHMWPE; b – BF; c – co-activation with BF for 2 minutes; d – co-activation with BF for 20 minutes.