Evaluation of Phase Morphology and its Impact on the Viscoelastic Response of Elastomer Blends

该项目的重点是更深入地了解未填充和填充弹性体共混物交联后相分离过程、相形态和相关粘弹性性能之间的相关性。一个主要目标是基于微观结构的spinodal分解建模和数值模拟，并从单独的相位特定测量中获得真实的物理输入参数。在此框架下，还将分析机械应力场对相形态的影响。进一步的目标是开发基于详细相形态的弹性体共混物高频粘弹性响应的物理驱动模型和仿真工具，例如畴和相间尺寸，填料分布和交联异质性。该项目分别建立在数值和理论（OvGU， DIK）以及实验（DIK）调查的两列基础上。在此，主要关注的是建立描述填料增强弹性体共混物复杂相行为的新概念。由于其物理动机和在数值工具中的良好实现，相场建模将成为选择的方法。实验重点在于评价控制相形态和填料分布的聚合物-聚合物和聚合物-填料热力学相互作用参数。此外，根据聚合物熔体的粘弹性和介电光谱估计了聚合物熔体的集体链迁移率，该模型适用于已建立的聚合物熔体中链重复的分子流变模型。

The project focuses on a deeper understanding of correlations between phase separation processes, the resulting phase morphology and related viscoelastic properties after crosslinking of unfilled and filled elastomer blends. One main objective is the microstructure based modelling and numerical simulation of spinodal decomposition with realistic physical input parameters obtained from separate phase-specific measurements. In this frame also the influence of mechanical stress fields on the phase morphology will be analysed. A further goal is the development of physically motivated models and simulation tools for the high-frequency viscoelastic response of elastomer blends based on the detailed phase morphology, e.g. domain and interphase size, filler distribution and crosslinking heterogeneities. The project is founded on two columns of numerical and theoretical (OvGU, DIK) as well as experimental (DIK) investigations, respectively. Herein, the main attention lies on the establishment of new concepts for describing the complex phase-behaviour of filler reinforced elastomer blends. Due to its physical motivation and the sound implementation into numerical tools, phase field modelling will be the method of choice. The experimental focus lies on the evaluation of thermodynamic polymer-polymer- and polymer-filler interaction parameters that govern the phase morphology and filler distribution. In addition, the collective chain mobility is estimated from viscoelastic and dielectric spectra of the poor polymer melts, which are adapted by a well-established molecular-rheological model of chain reptation in entangled polymer melts.