Assessment of carbon nanotube dispersion and mechanical property of epoxy nanocomposites by curing reaction heat measurement

The dispersion state of carbon nanotubes (CNTs) is a key parameter to the mechanical properties of nanocomposites. In the previous work, we proposed a method to assess the dispersion state of CNTs in a thermoset polymer matrix by measuring the curing reaction heat. In the present paper, we propose new parameters to represent the degree of CNT dispersion which can be defined from dynamic scanning calorimetry (DSC) measurement data. Then, we investigate a relationship among the degree of CNT dispersion, the curing reaction heat and the mechanical property of nanocomposites. A micromechanics model is proposed to predict the tensile modulus of nanocomposites considering not only the content but also the degree of dispersion of CNTs which is represented in terms of the curing reaction heat. The model predictions and experimental measurement data for the tensile modulus of nanocomposites show that the exothermic reaction heat during the curing process is a good quantitative measure to estimate the mechanical property of nanocomposites as well as to evaluate the degree of CNT dispersion.