Coarse grain modeling of polyimide copolymers

Addressing the wide span of timescales, where various important phenomena takes place in a polymer system, is inconceivable through a typical molecular dynamics simulation. Coarsening of simpler polymer systems has demonstrated significant potential in computationally characterizing and simulating systems at larger timescales. Addressing the need to extend existing coarsening methodologies on multifunctional materials to help design future generation materials is both promising and challenging. In this paper we present development of an atomistically informed coarse grain bead model of piezoelectric polyimide copolymers for large-scale simulations of thermal, mechanical and especially electrical properties. The coarsening approach generated a gain of two and a half orders of magnitude in terms of computational time and an order of magnitude gain in system size (equivalent to ∼ 360,000 atomistic model) while retaining the physical characteristics specific to the piezoelectric polymer. Reasonable agreement was observed between simulation results of the coarse grained and the atomistic model. Specifically mechanical moduli, density, dielectric constant, yield behavior, work hardening, response under dynamic loading and glass transition behavior were analyzed and compared.