Understanding multicomponent diffusion in polymers on the molecular-scale could lead to optimization of many practical processes. One important example is the removal of a toxic chemical (penetrant) from polyurethanes, which serve as the binder in many coatings technologies. This work is an equilibrium molecular dynamics (MD) study to characterize the molecular-scale hydrogen bonding (H-bonding) interactions in ternary penetrant, solvent, and polyurethane systems, and how these H-bonds influence the corresponding diffusivities. Homomorphic series of penetrant and solvent species in which molecular size and shape are kept constant while varying polarity or number of H-bonding sites are used to study the influence of hydrogen bond probability and strength on diffusivity. It is found that H-bonding between all species in the ternary mixture as well as penetrant-solvent collisions play a role in determining penetrant diffusivity. The findings provide insight into solvent selection criteria to increase the diffusivity of H-bonding penetrants that are absorbed in polyurethanes for extraction and decontamination applications.

在分子规模上理解聚合物中的多组分扩散可能会导致许多实际过程的优化。一个重要的例子是从聚氨酯中去除有毒化学物质（渗透剂），聚氨酯在许多涂料技术中均作为粘合剂。这项工作是一项平衡分子动力学（MD）研究，旨在表征三元渗透剂，溶剂和聚氨酯体系中分子级氢键（H-bonding）的相互作用，以及这些H键如何影响相应的扩散性。使用渗透性和溶剂物种的同态系列，其中分子大小和形状保持不变，同时改变极性或氢键位点的数量，以研究氢键概率和强度对扩散率的影响。发现三元混合物中所有物种之间的氢键以及渗透剂与溶剂的碰撞在决定渗透剂扩散性方面发挥了作用。这些发现为深入了解溶剂选择标准提供了依据，以提高在聚氨酯中吸收的H键渗透剂在扩散和去污应用中的扩散性。