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

Abstract

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 Sest ak-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.,

Modelling of Process-Induced Deformation for Composite Parts Considering Tool-Part Interaction

“…The thermo-chemical model for anisotropic composite materials includes the heat transfer model, internal heat model and the reaction kinetic equations. The governing equation of the thermo-chemical model can be expressed as follows [ 14 ]: where k x , k y and k z are thermal conductivity coefficients of the composite; ρ and C are the density and the specific heat capacity coefficient of the composite, respectively; T is the transient temperature; Q is the internal heat generated by the chemical reaction of the resin, which can be determined as follows [ 14 ]: where ρ r is the resin density; V f is the fiber volume fraction; H r is the total amount of heat generated by the resin during curing; α is the cure degree; dα /dt is the cure rate, and the cure kinetic equation of 3900-2 resin is defined as [ 32 ]: where the gas constant R is 8.314 J/mol·K; A and Δ E are the pre-exponential coefficient and the activation energy, respectively; m and n are the exponential constants. The thermal properties of T800HB/3900-2 composite are taken from the Toray Company and are given in Table 1 .…”

“…In this paper, the residual stress generated by the tool-part interaction in the viscous stage was calculated. Then, the stress increment equation of a new path-dependent constitutive model can be determined as follows: where α gel is the cure degree at the gelation point, and its value is 0.518 for 3900-2 resin [ 32 ]. T g for T800HB/3900-2 composite can be approximately expressed as: …”

Synthesis, characterization, and properties of silicone grafted epoxy/acrylonitrile butadiene styrene/graphene oxide nanocomposite with high adhesion strength and thermal stability

“…[ 52,53 ] Phenomenological models do not provide comprehensive information about the reaction path, but are used due to their simplicity and avoidance of difficulties in obtaining the parameters of mechanistic models. [ 54 ] Among these models, Kissinger, Ozawa, FWO and Friedman are well known to study the thermal degradation reaction of epoxy resin. Kissinger provides a simple and direct method to obtain activation energy.…”

Non‐isothermal DSC curing kinetics study of silicone‐modified epoxy/ABS/GO nanocomposite

“…The curing kinetics of the thermoset epoxy resins can be explored by thermal analysis methods. Differential scanning calorimetry (DSC) is one of the analysis methods with extensive application in the field of chemistry 19,22 . This approach is applied to determine the variations in the enthalpy and specific thermal capacity of a chemical reaction (either endothermic or exothermic).…”

“…Condensation reaction between the epoxy resin and MPS resin can alter the curing reaction with consumption of hydroxyl and epoxy groups. Also the curing reaction of epoxy resin can be changed in the presence of ABS 17–19 . GO can act as a catalyst for ring‐opening of epoxy group in the epoxy/amine system due to the presence of functional groups in the corners and the surface of it.…”