Two-dimensional simulation of crystalline growth fronts in a polypropylene/glass-fibre composite depending on processing conditions

Abstract

The application of a mechanical stress at the glass-fibre/polypropylene interface during cooling of the matrix may give rise to different crystalline superstructures, depending on the stress intensity and temperature. For a given stress-intensity/temperature combination, the transcrystalline phase growing in the vicinity of the fibre may have an α monoclinic or a β hexagonal crystallographic nature. On that account, variable boundary lines may be observed between a transcrystalline superstructure and the bulk spherulites. The intersections between the crystalline entities are calculated, and their computer simulations may be generalized to represent a multifilament wick in a unidirectional composite material. Knowledge of the application temperature of the mechanical stresses, and of the statistical distribution of the crystallization nuclei in the bulk, allows us to predict and to simulate the total crystalline morphology of a polypropylene/glass-fibre composite material. Finally, the model proposed is compared with experimental results.