Time, temperature and water aging failure envelope of thermoset polymers

• Published in: Polymer testing 2023-01, Vol.118, p.107901, Article 107901
• Main Authors: Gibhardt, Dennis, Krauklis, Andrey E., Doblies, Audrius, Gagani, Abedin, Sabalina, Alisa, Starkova, Olesja, Fiedler, Bodo
• Format: Article
• Language: English
• Subjects: Accelerated testing; Composite; Creep; Strength; Thermo-mechanical behavior
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2022.107901

Epoxies and epoxy-based fiber reinforced polymers (FRP) are significantly affected by environmental impacts during their service life. Exposures to water, humidity, temperature and UV radiation are known to substantially influence the (thermo-) mechanical properties and durability of the materials. Design-relevant characteristics like strength, stiffness, or the glass transition temperature change with time. Therefore, expensive test campaigns are often necessary in advance of a structural design. Prediction models based on physical relations or phenomenological observations are typically required to reduce costs and increase reliability. Consequently, a combined methodology for fast prediction of long-term properties and accelerated aging purposes is presented in this work for a common DGEBA-based epoxy. Therefore, master curves are obtained by creep and constant-strain-rate tests under temperature and moisture impact. A combined time–temperature–water superposition and the Larson–Miller parametrization demonstrate that time-saving CSR tests and modeling can replace long-lasting creep testing. Resulting, the presented methodology allows to determine a polymer’s entire (environmental) failure envelope in a relatively short time and with low testing effort. •Long-term durability prediction of epoxy by combination of testing and modeling.•Analysis of environmental impacts on epoxy by time–temperature–water superposition.•Substitution of time consuming creep master curves by constant strain rate tests.•Efficient and time-saving methodology for polymer design and construction.