Multiscale Simulation Study on the Synergistic Antioxidant Interaction of Complex Antioxidants in ABS Resin

In this work, the synergistic interactions of the primary antioxidants octadecyl 3-(3,5-ditert-butyl-4-hydroxyphenyl) propionate (1076), poly(dicyclopentadiene-co-p-cresol) (CPL), and auxiliary antioxidant didodecyl thiodipropionate (DLTP) within an acrylonitrile-butadiene-styrene (ABS) matrix were characterized at the molecular level. The synergism among these three antioxidants was demonstrated. The transition state of the antioxidant reaction and the chemical antiaging performance were characterized by quantum mechanical (QM) analysis. The compatibility of the antioxidants with the polymer matrix was confirmed by molecular dynamics (MD) simulations. Based on the results of multiscale simulation, an improved parameter equation to assess interactions among the three-component antioxidants was proposed. The optimal mole ratio of the ternary compound antioxidant (1076: CPL: DLTP) with the best antiaging performance in ABS was predicted to be 1:2:2 by the equation. Meanwhile, simulations proved that the complex antioxidant (1076: CPL: DLTP) system at a ratio of 1:2:2 presented a high binding energy and low molecular mobility and proved the optimal mole ratio of the ternary compound antioxidant.