Understanding the effect of CNT characteristics on the tensile modulus of CNT reinforced polypropylene using finite element analysis

The focus of this study is to understand the reinforcing efficiency of carbon nanotubes (CNT) in polymers through finite element modeling. The novelty of our work is that the probability distribution functions of CNT diameter, orientation, dispersion and waviness, determined through image analysis, are incorporated in the finite element model allowing thus for fundamental understanding of how the CNT characteristics affect the tensile modulus of CNT reinforced polypropylene (PP) composites. The presence of interphase, confirmed by atomic force microscopy, is also accounted for in our model. The image analysis approach utilizes scanning electron microscopy images of the CNT/PP composites made by melt mixing and injection molding. Model predictions are compared with the data obtained experimentally according to ASTM D638. A good agreement between the model predictions and experimental data is observed.