CHANGE OF THE MECHANICAL PROPERTIES DUE TO THE WATER AND SEAWATER ABSORPTION IN CASE OF SOME COMPOSITE MATERIALS

Abstract

The paper describes the aspects concerning decreasing of the mechanical properties of the glass-reinforced resins due to the water and seawater absorption. In this paper E-glass fibres were used to randomly reinforce polyester resins (Heliopol 8431 ATX, Polylite 440-M880), epoxy resin (LY554) and vinyl-ester resin (ATLAC 582). Specimens for tensile test and flexural test were manufactured. Two different environments (water and natural seawater from the Black Sea) were considered. Then, the specimens were subjected to a tensile test and flexural test (using the three-point method). Results of the tests applied on the specimens after immersion time were compared with the results obtained in case of the dry specimens. Herein, we show that the moisture acts on the strength and stiffness characteristic of the composite materials involved. We note that the moisture absorption into the composite materials analysed leads to the decreasing of the mechanical characteristics.