In “soft–soft nanocomposites” based on film formation of latexes with structured particles, the combination of particle structure and interparticle crosslinking leads to materials that behave as nonlinear viscoelastic fluids at small strains and as highly elastic networks at larger strains. Similarly, in studies of flow-induced crystallization in polymers, a two-phase model is often invoked in which a soft viscoelastic component is coupled with a rigid semi-crystalline phase providing stiffness. In the present work, we use the framework of non-equilibrium thermodynamics (NET) to develop stress-strain relationships for such two-phase systems characterized by a viscoelastic and an elastic component by making use of two conformation tensors: the first describes the microstructure of the viscoelastic phase while the second is related to the elastic Finger strain tensor quantifying the deformation of the elastic phase due to strain and is responsible for strain-hardening. The final transport equations are formulated in the context of the generalized bracket formalism of NET and can describe the rheological behavior and mechanical response of a large variety of soft materials ranging from rubbers to artificial tissues.

中文翻译：

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软两相弹性-粘弹性材料中应力-应变关系的非平衡热力学建模

在基于具有结构化颗粒的乳胶成膜的“软-软纳米复合材料”中，颗粒结构和颗粒间交联的结合导致材料在小应变下表现为非线性粘弹性流体，在大应变下表现为高弹性网络。类似地，在聚合物中流动诱导结晶的研究中，经常调用两相模型，其中软粘弹性组分与提供刚度的刚性半结晶相耦合。在目前的工作中，我们使用非平衡热力学 (NET) 的框架，通过使用两个构象张量，为这种以粘弹性和弹性分量为特征的两相系统建立应力-应变关系：第一个描述了粘弹性相的微观结构，而第二个与弹性手指应变张量有关，该张量量化了由于应变引起的弹性相的变形，并负责应变硬化。最终的传输方程是在 NET 的广义括号形式主义的背景下制定的，可以描述从橡胶到人造组织的各种软材料的流变行为和机械响应。