Efficient simulation of polymer melt viscoelasticity by dynamic Monte Carlo simulation

Abstract

Polymers have inundated modern society because of their tunable nature that makes them ideal for a wide variety of applications. Despite their prevalent use however, there are still many issues that are not understood due to the difficult nature of taking in situ measurements on the molecular scale. In order to address the molecular scale issue, this thesis presents the development of a dynamic Monte Carlo algorithm that is capable of capturing the salient details of polymer rheology. The algorithm used throughout the course of these studies is entitled the p-COMOFLO algorithm, thusly named because it modifies the Cooperative Motion Algorithm (also known as the COMOTION algorithm) to study flow and polydispersity. Throughout the course of this work the p-COMOFLO algorithm is developed which allows for the efficient simulation of polydisperse polymer melts subject to a wide variety of processing conditions including confinement, shear flow, parabolic flow, and extensional flow. The modification of the core Monte Carlo code to incorporate shear flow, parabolic flow, and extensional flow has been developed and subsequently implemented in an a priori manner. Utilizing these extensions, the p-COMOFLO algorithm is able to capture the molecular scale details of slip and cross-flow migration, which enables the evaluation and resolution of long standing polymer processing issues.