Modelling of morphology evolution and macroscopic behaviour of intercalated PET–clay nanocomposites during semi-solid state processing

Morphology evolution and macroscopic stress–strain behaviour of initially intercalated PET–clay nanocomposites during semi-solid state processing were predicted using a nonlinear two-dimensional computational model. The model combined different nanocomposite length scales into a computationally-efficient, continuum and nonlinear finite element framework. The main feature of the model is its nonlinear cohesive law proposed here to describe the gallery behaviour and the phenomenon of clay platelet slippage. Our model predicted: (1) shift in the onset of macroscopic strain-stiffening caused by the increased tactoid aspect ratio and processing temperature, and (2) quantified tactoid reorientation and clay platelet slippage as a function of applied strains and processing temperatures. Our predictions were found to be in a good agreement with experimental results, and therefore the model can be used in the optimisation of the processing of PET–clay nanocomposites.