Cure kinetics of epoxy resins and aromatic diamines

Abstract

SynopsisAn analysis of the cure kinetics of several different formulations composed of bifunctional epoxy resins and aromatic diamines was performed. A series of isothermal differential scanning calorimetry (DSC) runs (at higher temperature) and Fourier transform infrared spectroscopy (FT-IR) runs (at lower temperature) provided information about the kinetics of cure in the temperature range 18-160°C. All kinetic parameters of the curing reaction, including the reaction rate order, activation energy, and frequency factor were calculated and reported. Dynamic and isothermal DSC yielded different results. An explanation was offered in terms of different curing mechanisms which prevail under different curing conditions. A mechanism scheme was proposed to account for various possible reactions during cure.

Kinetic Analysis of Isothermal and Nonisothermal Epoxy‐Amine Cures by Model‐Free Isoconversional Methods

“…This problem has been addressed by several authors. [20][21][22] It is related to the use of kinetic methods that involve force fitting of nonisothermal data to hypothetical reaction models.…”

“…For E 1 < E 2 , we will obtain a decreasing evolution of E a /a and vice versa. Figure 7 shows the simulated E a dependency from Equation (21) using the values of the kinetic rate parameters extracted from the fitting of isothermal DSC data. It is worthy to note that the same E a versus a curve was obtained irrespective of the isothermal cure temperature that was considered in Equation (21).…”

“…Figure 7 shows the simulated E a dependency from Equation (21) using the values of the kinetic rate parameters extracted from the fitting of isothermal DSC data. It is worthy to note that the same E a versus a curve was obtained irrespective of the isothermal cure temperature that was considered in Equation (21). The simulated curve was found to closely match the actual E a values in the range of a ¼ 0-0.4, above which the two curves deviate more and more as a increases.…”

Kinetic study of the effect of catalysts on the curing of biphenyl epoxy resin

“…(4), several methods have been proposed. 5,6,10,13 Usually, on the parameters k 1 , k 2 , m, and n, they were calculated by fitting the experimental data to eq. the constant k 1 (4) in the first portion of cure up to 70-80% cure, constant of epoxy resin composition with DBU and TPP-TPB can be determined with Arrehedepending on the composition and the curing temperature.…”

Nonisothermal cure kinetics of DGEBA with novel aromatic diamine

“…Activation energies can be obtained from the slope. Ozawa-Flynn-Wall method based on Doyle's approximation 18,19 is an alternative method for the calculation of activation energy and is expressed as follows:…”