Dynamic mechanical and thermomechanical analysis of reversible plasticization of epoxy-diane resin-diaminodiphenylsulfon system by moisture

Abstract

Reversible influence of moisture on epoxy-diane resin DER-330 hardened by diaminodiphenylsulfon was investigated. Moisture transfer was modeled using Fick's second law. The influence of moisture evaporation on characteristic values of transfer temperature was analyzed. The Young dynamic modulus increased within the whole region of glassy state of epoxide polymer containing polyisocyanate additive which was dried after moistening. The transition region related to molecular mobility of kinetic segments interacting with moisture was found and characterized.

Effects of hygrothermal aging on the thermomechanical properties of a carbon fiber reinforced epoxy sheet molding compound: An experimental research

“…Equation ), its simplifications and derivatives have been widely employed by some authors to estimate and correlate water sorption in epoxy resins and composites 15,18,34,35 . If the diffusion coefficient remains constant during the water diffusion process, both sides of Equation ) can be derived in order to obtain the Fick's second law (Equation )). …”

“…Instead, it is proposed to use the minimum point of the temperature derivative of the storage modulus ( dE' / dT ) curve, based on the physical meaning that this point represents, that is, the maximum rate of the α‐transition 47 . Moreover, Startsev completes the T g analysis by plotting and checking the E' and E" curves 35,47–49 …”

“…47 Moreover, Startsev completes the T g analysis by plotting and checking the E' and E" curves. 35,[47][48][49] In this article, the plasticization effects generated by Type I hydrogen bonds have been analyzed by determining the variation in the T g values between dry and aged specimens. For this, the method proposed by Startsev et al 30 for stablishing T g has been employed and, at the same time, the suitability of this method for C-SMC materials has been validated.…”