Coarse-Grained Simulations of Crystallization and Mechanical Enhancement in Semicrystalline Polymer Interfaces with Block Copolymer Compatibilizers

We apply molecular dynamics (MD) simulations of coarse-grained bead-spring chains to investigate immiscible interfaces formed by semicrystalline polymers. Using simulations of isothermal crystallization, we demonstrate how immiscible interfaces with various interfacial widths can impact crystallization near the interfacial region. We show semicrystalline loops from different polymer domains rarely entangle near the interface, which leads to poor interfacial adhesion. Block copolymer compatibilizers, however, can strengthen the interfaces by forming semicrystalline tie-chains connecting crystallites across the interfaces. By varying the block copolymer architecture, length, and loading density in our simulations, we demonstrate how the compatibilizer design may impact the formation of stress transmitters, such as tie chains and entangled loops across the interfaces. Using simulated tensile tests, we also evaluate the enhanced mechanical performance of the block copolymer-enhanced interfaces. These findings offer important guidance for designing more effective compatibilizers to improve the mechanical strength of heterogeneous semicrystalline polymer samples.