This study focuses on the influence of prolonged ultraviolet (UV) irradiation on the mechanical properties and surface microstructure of glass fiber-reinforced plastics (GFRPs) and basalt fiber-reinforced plastics (BFRPs), which are widely used in construction and transport infrastructure. The relevance of the research lies in the need to improve the reliability of composite materials under extended exposure to harsh climatic conditions. Experimental tests were conducted in a laboratory UV chamber over 2000 h, simulating accelerated weathering. Mechanical properties were evaluated using three-point bending, while surface conditions were assessed via profilometry and microscopy. It was shown that GFRPs exhibit a significant reduction in flexural strength—down to 59–64% of their original value—accompanied by increased surface roughness and microdefect depth. The degradation mechanism of GFRPs is attributed to the photochemical breakdown of the polymer matrix, involving free radical generation, bond scission, and oxidative processes. To verify these mechanisms, FTIR spectroscopy was employed, which enabled the identification of structural changes in the polymer phase and the detection of mass loss associated with matrix decomposition. In contrast, BFRP retained up to 95% of their initial strength, demonstrating high resistance to UV-induced aging. This is attributed to the shielding effect of basalt fibers and their ability to retain moisture in microcavities, which slows the progress of photo-destructive processes. Comparison with results from natural exposure tests under extreme climatic conditions (Yakutsk) confirmed the reliability of the accelerated aging model used in the laboratory.

A relevant task in improving the properties of elastomers is to increase their strength and stiffness, which affect the reliability and durability of rubber products. The paper presents a technology for manufacturing high-modulus materials based on SKD-V butadiene rubber and reinforcing layers of fabrics from basalt, glass, and carbon fibers. The results of studying elastic strength properties reveal a significant increase in the ultimate strength of reinforced samples in comparison with an unmodified elastomer. The increase in tensile strength varies from 1.7 to 2.8 times. The addition of reinforcing layers reduced the elongation value by 25 to 47 times compared to rubber without reinforcement. High tensile strength and low elongation increase shear resistance. The wear resistance testing of elastomers coated with reinforcing fabrics shows a decrease in abrasion resistance reduced by a factor of 5.8. Abrasion wear and interaction between the reinforcing filler and the polymer are studied by electron microscopy. The study of the microstructure shows a weak contact between the fiber and the elastomeric matrix. Lack of contact during the abrasion process causes destruction of the fibers on the abrasive surface and their further separation. Due to the combination of high tensile strength and low elongation, the reinforced materials obtain high modulus properties combined with lateral mobility.

A fundamental challenge in composite materials engineering is insufficient adhesive bonding between the matrix and the filler, which significantly reduces product reliability and durability. To address this problem, chemical and physical surface modification of the filler is employed so that a strong bond can be created at the phase interface. This study examines the interaction between modified high-modulus fibers and an elastomeric matrix, specifically investigating the influence of surface treatment for basalt (BF) and carbon (CF) fabrics on the properties of elastomeric composites based on butadiene rubber. Two surface treatment methods were studied: a rubber compound solution in toluene (RCS) and Chemosil 411 adhesive. Microstructural analysis revealed that untreated samples delaminate at the BF/CF interface due to poor adhesion between the fabrics, whereas treated samples exhibit strong adhesion between the rein forcing fibers. Furthermore, the formation of a dense contact between the fibers and the elastomeric matrix was registered, which is attributed to the diffusion of rubber macromolecules during vulcanization. Mechanical testing demon strates that combined reinforcement with BF and CF increases composite strength by 4.9 times compared to the original elastomer, as this is related to effective load distribution across the fibers. While applying RCS to the fabric surface provides the highest strength, treatment with Chemosil ensures high stability in a hydraulic oil environment. Adhesion tests confirmed that Chemosil maintains the bond strength between BF and CF after hydrocarbon exposure because the adhesive layer acts as a protective barrier. However, under prolonged thermal exposure, all samples show reduced adhesive strength due to the degradation of both the polymer matrix and the adhesive layer; additionally, their hardness increases since additional cross-linking between rubber macromolecules occurs via post-vulcanization. In conclusion, the results prove that pre-treating basalt and carbon fibers with adhesives is effective for creating composites based on an elastomeric matrix and high-modulus fibers.