Coarse-Grained Molecular Dynamics Simulation of Polycarbonate Deformation: Dependence of Mechanical Performance by the Effect of Spatial Distribution and Topological Constraints

Polycarbonate is an engineering plastic used in a wide range of applications due to its excellent mechanical properties, which are closely related to its molecular structure. We performed coarse-grained molecular dynamics (CGMD) calculations to investigate the effects of topological constraints and spatial distribution on the mechanical performance of a certain range of molecular weights. The topological constraints and spatial distribution are quantified as the number of entanglements per molecule ([Formula: see text]) and the radius of gyration ([Formula: see text]), respectively. We successfully modeled molecular structures with a systematic variation of [Formula: see text] and [Formula: see text] by controlling two simulation parameters: the temperature profile and Kuhn segment length, respectively. We investigated the effect of [Formula: see text] and [Formula: see text] on stress–strain curves in uniaxial tension with fixed transverse strain. The result shows that the structure with a higher radius of gyration or number of entanglements has a higher maximum stress ([Formula: see text]), which is mainly due to a firmly formed entanglement network. Such a configuration minimizes the critical strain ([Formula: see text]). The constitutive relationships between the mechanical properties ([Formula: see text] and [Formula: see text]) and the initial molecular structure parameters ([Formula: see text] and [Formula: see text]) are suggested.