Phase-Field Model for Polymer Composite Solidification

Predicting the mechanical properties of polymer composites depends on the structure of the material formed during solidification. Materials engineers must investigate the dependence of these parameters on the geometric features of the composite, and this study does so with the Phase Field Method. This method has been developed for polymer solidification over approximately the past 25 years and is here used to produce 2D simulations of composites containing solid circular particles. Simulations were performed in MOOSE (Multiphysics Object-Oriented Simulation Environment) by (1) replicating a model from the literature then (2) modifying the geometry to include randomly distributed particles. The size and number of particles were varied in the simulations to understand their relationship to each other and the composite’s sensitivity to them. It was found that the visual distortion of the solidifying crystals is more sensitive to the number of particles than their size. Additionally, the liquid material often does not solidify onto the particles from the crystal side, which, as explained later and justified with the literature, is likely due to the nature of heat diffusion surrounding the particles. The simulations performed here give an understanding of crystallization in polymer composites and are foundational for predicting the mechanical properties of such materials.