Correlation between Wet Ageing, Humidity Absorption and Properties on CompositeMaterials Based on Different Resins Family

摘要

The material humidity content influence on the Interlaminar Shear Stress (ILSS)and on the glass transition temperature (T(sub g)) properties is pointed out. Three composite families were investigated: Bismaleimide (BMI), cyanate, and epoxy. Experimental data on humidity absorption show that for BMI and cyanate, the data can be fitted with Fick's law to follow the humidity absorption kinetics. For expoxy, the data can be fitted with Langmuir's law. Regarding the T(sub g) values, for the epoxy, the drop of T(sub g) between the dry state and the wet state occurs during the first step of humidity absorption. For the cyanate, the drop of T(sub g) appears during the last step of humidity absorption. For the BMI, no influence of humidity content on the T(sub g) values was noticed. Concerning the ILSS, for the epoxy a linear relationship between the humidity content and the ILSS was observed. For the cyanate, no influence of the humidity content on the ILSS was noted. For the BMI, a humidity content over 0.6 results in a important decrease of the ILSS.