Toughening mechanism of phthalonitrile polymer: MD simulation and experiment

Based on the demand for materials in the aerospace field, we are researching the brittleness problem of phthalonitrile resin (PN75), a high-temperature resistant resin material. Combining molecular dynamics simulations with experiments in time-consuming and costly studies has become a meaningful way to reduce research and development cycle time and cost. In a world where high-performance computer simulations are capable of enormous computational scales with guaranteed reliability, experiments and characterization at the atomic-molecular scale are still challenging tasks. Revealing microscale mechanisms through atomic simulations and providing guidance for laborious, time-consuming, and expensive experiments is one of the current scientific hotspots. The free volume pore distribution of PN75 was analyzed using molecular dynamics (MD) simulations to reveal the primary mechanism of PN75 during toughening. Improving the scalability of the free volume cavity of PN75 creates an appreciable energy dissipation mechanism. The combination of experimental and MD simulation results verifies the usefulness of simulation as a guide for experiments. MD simulations can reduce complex experimental and characterization efforts, reveal experimental mechanisms at the nanoscale, and guide the design of polymers.