Organic additive modification is a key technology for improving the arc-quenching performance of gassing materials

but additives are prone to migration and diffusion within polymers. Traditional experiments are costly and time-consuming

making efficient screening of a large number of additives difficult. This paper uses PA6 as the matrix and employs molecular dynamics to quantify the migration trajectory and its influence on the free volume of the matrix for more than 90 organic additives

establishing a structure-activity relationship model from the overall molecular level to the local atomic level. The results show that the structure-activity relationship model has an R2 value above 0.8

demonstrating good predictive generalization ability. Nitrogen-containing functional groups play a dominant role in inhibiting migration by forming strong intermolecular interactions with PA6

especially the strongly negative potential region (-38.69 kcal/mol) around the sp3 hybrid nitrogen atom in the piperazine ring

which gives it the highest polarity index (15.3 kcal/mol) and forms stable intermolecular hydrogen bonds with the amide hydrogen on the PA6 chain. At the same time

due to the competition between intramolecular and intermolecular hydrogen bonds

the effective interaction between the additive and the matrix is reduced

resulting in a nonlinear correlation between the migration behavior and apparent polarity/volume. The comprehensive evaluation method proposed in this paper

which combines molecular dynamics simulation and machine learning

can quantify the migration trend of additives in the nylon matrix. The structure-property relationship revealed provides key theoretical guidance for designing gassing materials with thermal stability and long-term reliability.