Kinetic and reactivity distribution behaviors during curing process of carbon/epoxy composite with thermoplastic interface coatings (T800/3900‐2 prepreg) under the nonisothermal conditions

In this work, the thermal stability, the non‐isothermal cure kinetics and distributed reactivity model (DRM) for fiber reinforced resin matrix composite (T800H/3900‐2 prepreg) have been systematically analyzed using combined phenomenological and partially fundamental approaches. It has been shown that the proposed actual kinetic model (expressed through the three‐parameter Šesták‐Berggren (SB) model including the diffusion effects) more accurately describes the curing process than the idealized kinetic model (which includes only the autocatalytic reaction). Presence of diffusion phenomena that occur at elevated temperatures and higher values of the extent of cures were demonstrated and explained in detail, through the use of modified Williams–Landel–Ferry (WLF) equation (based on the glass transition analysis) and the Avrami crystallization theory. The DRM was demonstrated that in autocatalytic stage, the reaction of primary amine with two epoxy groups plays an important role in the overall curing process. It has been shown that condensed phase effects can lower the apparent activation energy ( E _a ) value of the curing process. The lifetime analysis showed that the studied T800H/3900‐2 prepreg possesses good thermal resistance, which is connected with the process including a ring‐opening addition‐type crosslinking reaction.POLYM. COMPOS., 39:201–220, 2018. © 2016 Society of Plastics Engineers