Canadian Journal of Chemical Engineering, Vol.92, No.4, 703-711, 2014
Modelling of Curing Kinetics of Amine Cured Epoxy Resins for Vacuum Assisted Resin Infusion Molding
Epoxy resin, along with a suitable reinforcement such as glass, is used to manufacture windmill blades by vacuum assisted resin infusion molding (VARIM) process. For the simulation of VARIM process, the sub models are required to describe the rheological and thermochemical behaviour of the epoxy resin. In the present paper, the curing kinetics of amine cured epoxy resin, which is mostly used for wind blade manufacturing, are presented. The kinetic study is performed by measuring the exothermal heat generated during the curing of the amine cured epoxy resin system, using Differential Scanning Calorimeter (DSC), at different temperatures. The range of the temperature for the study is selected between the reaction onset temperature, which is about 70 degrees C, and the peak reaction temperature, which is nearly 120 degrees C. The reaction exotherm, as measured by DSC, is processed to obtain the reaction kinetic data such as the degree of reaction and the rate of reaction at different times and temperatures. A suitable model is proposed to describe the reaction kinetic data obtained experimentally. The unknown parameters of the models are determined by a nonlinear regression analysis on experimental data, while the kinetic rate constants are obtained based on Arrhenius Law. The proposed model is also compared with the models available in the literature. It is found that the proposed model is the simplest model, which accurately captures both the degree of cure and rate of cure qualitatively and quantitatively.
Keywords:polymer chemistry;kinetics and mechanisms of reactions;mathematical modelling;composites;materials science and technology;polymers;rubber and plastics