Differential Scanning Calorimetry study on curing kinetics of diglycidyl ether of bisphenol A with amine curing agents for self-healing systems

Abstract

Epoxy resin is one of the most important polymeric matrixes for diverse uses, such as aeronautical, mobile, electronics and others. Providing a material capable of self-healing microcracks will allow it to have a more reliable and longer use. In order to study this new property of self-healing to an epoxy resin, a Differential Scanning Calorimetry (DSC) study was carried out to measure physical chemical properties such as activation energy, enthalpy of polymerization, order of reaction and pre-exponential factor based on an Arrhenius equation modelling. The materials used are diglycidyl ether of bisphenol A (DGBA) as the core material, triethylenetetramine (TETA) and an aminated polydimethylsiloxane (ADM), as curing agent and poly(urea-formaldehyde) (PUF) as microcapsule wall. Tests were done by dynamic and isothermal DSC of systems containing the resin and microencapsulated curing agent and also the resin with the free curing agent. The results showed the necessity of heating for the cure and the self-healing to be initiated.

Microencapsulated amino‐functional polydimethylsiloxane as autonomous external self‐healing agent for epoxy systems

“…A detailed study of curing kinetics for the DGEBA/TETA and DGEBA/PDMS‐a systems, by DSC measurements, have been published elsewhere . Here, a DSC study of a DGEBA/PDMS‐a/TETA system, consisting of PDMS‐a/TETA in a 50/50 (m/m) ratio mixed with an equimolar amount of DGEBA, is presented in Figure .…”

The effects of residual organic solvent on epoxy: modeling of kinetic parameters by DSC and Borchardt-Daniels method

“…From data obtained by DSC dynamic tests, the Borchardt-Daniels method were used to analyze the kinetics involved on the curing process since this model can be performed from only one DSC dynamic run [33] . In order to study kinetics parameters of the curing reactions some considerations must be taken into account.…”

“…Another consideration is that the velocity constant k(T) is temperature dependent and follows the Arrhenius expression. Therefore, the Equation 2 can also be adapted follow the relation described on the Equation 3, which relates the reactions rate (dα/dt) with the curing degree (α), reaction order (n), pre-exponential factor (A), activation energy (E a ), the ideal gas constant (R) and the temperature (T) [22,33] .…”