Determining the role of interfacial transcrystallinity in composite materials by dynamic mechanical thermal analysis

The ability of this research group to obtain specimens of isolated transcrystalline layer by microtoming, reported in this paper for the first time, has opened a window for a range of characterization techniques. Here, the interfacial transcrystallinity in aramid fibre-reinforced nylon 66 microcomposites is studied using dynamic mechanical thermal analysis. The results show that the viscoelastic energy damping of the transcrystalline layer, tanδ_tc = 0.064, is smaller while the elastic modulus,E′_tc = 4.6GPa, is higher compared with the crystallized matrix. Moreover, the magnitude of the energy damping by the transcrystalline layer could be used in a rule-of-mixtures expression to calculate the energy damping of an aramid fibrereinforced nylon 66 microcomposite. It is also shown that the activation energy for relaxation, corresponding to the energy barrier for polymer chain movement, increases in the presence of reinforcement and transcrystallinity.