Study on the hygrothermal aging behavior and diffusion mechanism of Ti/CF/PMR polyimide composite laminates

A series of hygrothermal aging experiments were performed on Ti/CF/PMR polyimide (TCPP) composite laminates in this work in order to verify the moisture diffusion characteristics and diffusion mechanism of the laminate. The specimens were subjected to various hygrothermal aging parameters, specifically 70 °C/95RH%, 85 °C/75RH%, 85 °C/85RH% and 90 °C/95RH%. The results illustrate that the temperature affected the diffusion rate of water molecules in the composite laminates, and the relative humidity determined the saturated moisture absorption rate. For the orthogonally laminated TCPP composite laminates, two equations have been obtained to predict the saturated moisture absorption and diffusion rate of water molecules of the prepreg layer. Additionally, the moisture absorption as a function of time has been expressed for the prepreg layer. (paper)