Modelling Flow and Crystalisation in Polymers Developing Molecular Models and Simulations: Polymer Dynamics and Phase Transitions

In this thesis we aim to further develop the understanding of polymer crystallisation by developing molecular models and simulations for polymer dynamics and phase transitions using a range of analytical, numerical and stochastic techniques. Complexities arise in polymers dynamics since polymers are composed of long chain molecules, and utilising models that capture interactions between these chains leads to properties that are unique to the field of polymer rheology. Many polymer fluids crystallise when cooled, a feature that they share with simple fluids, but the crystallisation process itself is significantly different as it affected by the way the constituent chains are connected, leading to a multitude of unexplained phenomena. Furthermore, if a polymer fluid is placed under flow, both the ease with which the polymer crystallises and the arrangement of the polymer chains within the resulting crystal can differ greatly. This nucleation mechanism is not very well understood, and thus the area of polymer crystallisation would benefit from the creation of models that incorporate the unusual behaviour of polymers.