Hygrothermal Aging History of Amine-Epoxy Resins: Effects on Thermo-Mechanical Properties

Epoxy systems are widely used as matrix resins for fiber reinforced polymers (FRP) and, therefore, often have to withstand harsh environmental conditions. Especially in marine and offshore environments, moisture or direct water contact leads absorption into the epoxy resin. As a result, mechanical properties change during application. Since diffusion at room colder temperatures is slow, industry academia typically use accelerated aging methods elevated durability prediction. However, water-polymer interaction complex combination of plasticization, physical aging, molecular interaction, all these mechanisms expected be affected by ambient temperature. To reveal impact time temperature on thermo-mechanical an amine-epoxy system, this publication includes various hygrothermal conditions, like bath relative humidity ranging from 8°C 70°C 20% 90%. Thus, it demonstrated via long-term DMTA FTIR investigations that, e.g., strength, stiffness, strain failure, glass transition (T g ) can differ significantly depending For example, shown that cold strongest longest-lasting reduction although maximum amount lower than higher temperatures. application, means strength differences up 26% obtained, method selected. Furthermore, conventional prediction models, such Eyring correlation, which consider mobility structure properties, only limited extent aging. The reasons seen be, particular, different characteristics interactions While plasticization dominates relaxation strong water-molecule bonds predominate warm