Investigation of the formation of external surface layers in epoxy composites

Sustainable Transport Reliability: Exploring the Creep of Eco-Friendly Polymer Nanocomposites

“…As mentioned earlier, the addition of a fibrous filler enhances the cohesive properties of composites by altering the molecular mobility in the adsorption layer surrounding the fibers during the initial stages of composite formation. Simultaneously, the incorporation of a dispersed additive facilitates both chemical and physical interactions at the phase separation boundary, owing to the presence of active centers on the surface of particles, which leads to changes in the conformational arrangement of macromolecules in the matrix's surface layers surrounding the filler [17,18]. This interaction is significantly enhanced through the pre-drying of fabrics according to predetermined temperature and time conditions, resulting in a subsequent reduction in the creep rate of the studied materials.…”

“…The authors [10][11][12][13][14][15] have demonstrated that using polymer CMs substantially enhances the physical and mechanical properties and the wear resistance of transportation components exposed to aggressive environments. Consequently, this significantly extends the service life of mechanisms and machines, contributing to their reliability [16][17][18][19][20]. Based on these findings, it can be affirmed that the investigation of the effects of static loads on the alteration of the physical and mechanical properties of materials during operation, while considering environmental safety concerns, stands as a critical objective in contemporary polymer materials science.…”

Regularities of Impact Failure of Epoxy Composites with Al₂O₃ Microfiller and their Analysis on the Basis of External Surface Layer Concept

“…In addition, the following sublayers are distinguished in the polymer OSL around the surface of the filler particles: adsorption microlayer (1…10 nm), oriented layer (~0.7 µm), transient layer (defective polymer layer), and polymer in the voluminous phase. It was shown before [5,7] that the adsorption layer (1…3 µm) and the OSL (3…40 µm) are formed around the filler particles. It is obvious that the degree of the polymer cross-linking in the OSL is the key factor in increasing the ECM strength (Fig.…”

“…It was shown that the effect of composites hardening in the presence of a filler is determined, to a large extent, by the structure of the boundary layer and the strength of the adhesive interaction between the filler particles and the polymer [5,7,8]. It was shown earlier that a polymer layer near the phase boundary differs by its properties and structure from the bulk of polymer.…”

“…Impact toughness was determined with the use of specimens made of ECM. The object under study was the commercial epoxy oligomer ED-20 (GOST 10587-84), which is characterized by high cohesive strength, low shrinkage, and good processing characteristics when applied to the surface of the composite profile [7]. Polyethylenepolyamine PEPA (TU 6-05-241-202-78) was used as a hardener in the process of polymerization of epoxy compositions.…”