The influence of UV radiation on the properties of GFRP laminates in underwater conditions

• Published in: Scientific reports 2024-03, Vol.14 (1), p.7446-11, Article 7446
• Main Authors: Smoleń, Jakub, Olesik, Piotr, Nowacki, Bartłomiej, Godzierz, Marcin, Kurtyka, Klaudia, Chaber, Paweł, Czakiert, Jan, Kozioł, Mateusz
• Format: Article
• Language: English
• Subjects: 639/301; 639/301/930; Aquatic environment; Degradation; Environmental degradation; Fibers; GFRP laminates; Glass fibers; Humanities and Social Sciences; Mechanical properties; multidisciplinary; Polymer matrix composites; Polymers; Radiation; Science; Science (multidisciplinary); Styrene; Synergistic effect; Ultraviolet radiation; Underwater; Unsaturated polyester resin; UV degradation
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-57999-8

Degradation of polymer composites is a significant problem in many engineering aspects. Due to the interaction of various degradation factors during the exploitation of composites, a synergistic effect of destruction is observed. The article describes the phenomena occurring in glass fiber reinforced polyester laminates under the influence of ultraviolet radiation (UV) in an aquatic environment. The laminates were exposed to UV-A, UV-B and UV-C radiation for 1000 h in free-air and underwater conditions. During the test, the materials were immersed at stable depth of 1 mm and 10 mm, respectively. The three-point bending tests performed on the samples after being exposed to UV showed an increase in the flexural strength of the composites. Simultaneously, degradation of the outer surface layer was observed. The degradation removed the thin resin film from the surface which resulted in a direct exposure of the reinforcing fibers to the environment. The transformations taking place in the deeper layers of the composite increased the mechanical strength due to the additional cross-linking reactions excited by the energy arising from the radiation. Moreover, the formation of polymer structures from free styrene remaining after the technological process and the occurrence of free radical reactions as a result of the cage effect was also observed.