The hygrothermal aging process and mechanism of CFRP papered by prepreg that may be stored at room temperature

•Have prepreg with excellent performance and ability to be stored at room temperature ready.•Consistently study the hygrothermal aging performance of CFRP.•Anticipate the natural lifespan of carbon fiber composites to exceed 60 years. In this research, we investigated the hygrothermal aging process and mechanism of carbon fiber reinforced plastic (CFRP) prepared by prepreg and suitable to be stored at room temperature. By submerging CFRP in distilled water under different temperatures, we have conducted moisture absorption, chemical structure, mechanical properties, fracture morphology, thermal properties and lifespan prediction of CFRP. The prepreg system may be stored for at least 60 days at room temperature, due to the results of FT-IR and DSC analysis. The moisture absorption is increased linearly with the square root of aging time; it follows the Fick's second law. An important part in the hygrothermal aging of CFRP is taken by plasticization and degradation. It is predicted by the residual strength model, that the lifespan under natural conditions is greater than 60 years. We believe that this study can benefit the extensive and safe application of prepreg that is suitable to be stored at room temperature in engineering application.