Atomistic Simulation of a Thermoplastic Polyurethane and Micromechanical Modeling
Thermoplastic polyurethanes constitute a versatile family of materials with a broad variety of engineering applications. However, connection between their chemical structure and mechanical properties remains elusive, in large part due to their heterogeneous nature, arising from segregation of chemically distinct segments into separate domains, with resulting complex morphologies. Using atomistic simulations, we examine the structure and mechanical properties of a common family of thermoplastic polyurethanes (TPU) comprising 4,4' diphenylmethane diisocyanate and n butanediol (hard segment) and poly(tetramethylene oxide) (soft segment) A lamellar stack model previously developed for the study of semicrystalline polymers is applied here for the first time to a phase segregated copolymer. Equilibrium structure and properties were evaluated for TPUs with different ratios of hard and soft components, using a combination of Monte Carlo and molecular dynamics simulations. Stress strain behaviors were then evalua.