Abstract The formation of the interpenetrating polymer network (IPN) structure within the cement-polymer system has been revealed by experiments from 2 dimensional to 3-dimensional scales. However, the microstructure design and performance prediction of IPN as a function of specific C-S-H/polymer components or ingredients' parameters e.g. water to cement ratios (w/c), polymer to cement ratios (p/c), monomer components, degree of polymerization (DP), etc. is by far not available. Here we developed a mesoscale model for IPN visualization based on the Flory-Huggins interaction theory which was applied to cement science for the first time. All the ingredients in the micro-structure were considered as soluble beads with rational sizes based on their properties obtained by molecular dynamic methods. The interaction parameters of each bead were then determined based on their element ratios and chemical backbones. The model was validated with the waterborne epoxy-cement material (WECM) in which a novel waterborne epoxy resin (WEP) was prepared and impregnated. The verification results on the 2D-3D scale show that the developed model predicts the WECM's IPN structures by rule and line concerning DP, w/c, and p/c in the mixture. The C-S-H beads were progressively scaled in size which alters the C-S-H texture to have completely different dissolution characteristics. Beads of diameter ~6 A are more unstable and soluble which enable them to form a continuous phase in water or a composite structure with WEP. In contrast, beads with diameters larger than 10 A have different properties with stronger nucleation effects. The results also suggest the impregnation content of WEP in cement-based material should be limited to 10% vol. to prevent the polymer IPN from decomposing into discrete clusters. The application of Flory-Huggins theory in cement-based composites demonstrates great potential in performance prediction and microstructure design.

中文翻译：

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水泥浆-水性环氧体系中的互穿聚合物网络

摘要 通过从 2 维到 3 维尺度的实验，揭示了水泥-聚合物体系内互穿聚合物网络 (IPN) 结构的形成。然而，作为特定 CSH/聚合物组分或成分参数的函数的 IPN 的微观结构设计和性能预测，例如水与水泥的比率 (w/c)、聚合物与水泥的比率 (p/c)、单体组分、聚合度(DP) 等目前尚不可用。在这里，我们基于 Flory-Huggins 相互作用理论开发了一个用于 IPN 可视化的中尺度模型，该模型首次应用于水泥科学。根据分子动力学方法获得的性质，微观结构中的所有成分都被认为是具有合理尺寸的可溶性珠粒。然后根据它们的元素比率和化学骨架确定每个珠子的相互作用参数。该模型使用水性环氧水泥材料 (WECM) 进行了验证，其中制备并浸渍了一种新型水性环氧树脂 (WEP)。在 2D-3D 尺度上的验证结果表明，开发的模型通过关于混合物中 DP、w/c 和 p/c 的规则和线来预测 WECM 的 IPN 结构。CSH 珠粒的尺寸逐渐按比例缩放，这改变了 CSH 的质地，使其具有完全不同的溶解特性。直径约 6 A 的珠子更不稳定，更易溶解，这使它们能够在水中形成连续相或与 WEP 复合结构。相比之下，直径大于 10 A 的珠子具有不同的特性，具有更强的成核效应。结果还表明，WEP 在水泥基材料中的浸渍含量应限制在 10% vol。以防止聚合物 IPN 分解成离散的簇。Flory-Huggins 理论在水泥基复合材料中的应用显示出在性能预测和微观结构设计方面的巨大潜力。