Modeling thermoset polymers using an improved molecular dynamics crosslinking methodology

Abstract

This research explores the exceptional capabilities of an improved proximity-based molecular dynamics technique for modeling the crosslinking of thermoset polymers. The novel methodology enables realistic curing simulations through its ability to dynamically and probabilistically perform complex topology transformations while selectively minimizing high potential energy groups. The molecular structures are analyzed based on the incorporation of cure temperature, cutoff distance, and reaction probability into the Arrhenius equation, providing important insights into the pitfalls of some commonly used assumptions in crosslinking simulations. In addition, this work discusses the necessity of using thermal disturbance to break metastable configurations. Finally, a variety of these systems are tested for their ability to capture the effects of temperature and crosslinking degree on material properties. This leads to new perspectives for the strain hardening phenomenon, the sensitivity of stiffness calculations, and the evolution of the Poisson’s ratio, and provides a holistic view of the glass transition temperature through its manifestation in each of these mechanical properties.