Structural elucidation of network effects in highly filled polymers

用活性填充剂、功能性填充剂或非活性填充剂对现有技术热塑性塑料进行改性是一种经济有效且常用的方法。在现代聚合物加工中，将不同的聚合物与填料混合也是开发新型聚合物的重要途径。改性的目的始终是改变材料的物理性能。这样，活性填料能够提高力学性能，弹性填料能够提高伸长行为。导电填料改善了例如聚合物的导电性和/或导热性。聚合物中所有改性剂的高度均匀度对于实现所需的性能非常重要。此外，由于加工性的改变，改性剂只应可忽略地改变未改性聚合物的流动性。到目前为止，普遍的认识是，高填充聚合物在低剪切速率下的屈服行为是由颗粒网络引起的。文献中经常谈到粒子-粒子的相互作用，这还没有用图像来研究。一些来源报告图像，但不能证明粒子-粒子网络。本研究项目的目的是全面了解不同填料在不同聚合物中的三维网络结构。如果像文献中描述的那样，这些三维网络中的一些被比喻地驳斥了，尽管屈服行为发生了，申请者的假设应该得到深入的研究。这些研究主要集中在一方面区分基质中不同的极性和非极性配对的影响，其次是使用靶向的低分子量(较短的分子链)来减少颗粒环境的影响。因此，最初，具有不同选择的添加剂几何形状的各种材料-添加剂组合通过复合过程来组合。在低剪切速率下，屈服行为应该发生，并且可以用流变仪来实现。在这种状态下，样品被冷却，并将使用所有三个维度的各种方法进行形态分析。依赖于变形大小的结构的量化也可以用分维来量化。为此，除了扩展结构分析之外，还使用了无损检测。通过无损检测手段对颗粒结构进行表征甚至有可能在工业应用中用作在线监测工具。

The modification of existing technical thermoplasts with active fillers, functional fillers or inactive fillers is a cost effective and commonly used way. Blending of different polymers with fillers is an essential way to develop new polymers in modern polymer processing, as well. Goal of the modification is always the change of physical properties. In this way active fillers are able to enhance the mechanical properties and elastic fillers are able to enhance the elongation behavior. Conductive fillers improve for example the electrical and/or the thermal conductivity of polymers. A high homogeneity of all modifiers in the polymers is very important in order to achieve the desired performance. Additionally, the modifiers should only change negligibly the flowability of the unmodified polymer due to changes in the processability. Up to now the common knowledge is, that the yielding behavior at low shear rates of highly filled polymers is caused by particle networks. The literature talks often about particle-particle interactions, which have not been investigated by images. Some sources report images, but cannot proof a particle-particle network. The aim of this research project is the gain comprehensive knowledge of the three-dimensional network structures of different fillers in various polymers. If - as has been described in the literature - some of these three-dimensional networks are refuted figuratively, although the yielding behavior occurs, the hypothesis of the applicant to should be investigated intensively. These studies are focused on the one hand distinguish the effects of different pairings of polar and nonpolar partners of matrix and secondly targeted lower molecular weights (shorter molecular chains) are used to reduce the influence of the particles environment. Thus, initially, various material-additive combinations with different selected additive geometries are combined by a compounding process. At low shear rates the yield behavior should occur and can be achieved with a rheometer. In this state, the samples are cooled and will be morphologically analyzed using various methods in all three dimensions. Quantification of structures depending on the deformation size can be quantified by the fractal dimension, as well. For this purpose the non-destructive testing is used in addition to extend the structural analysis. The characterization of the particulate structure by means of nondestructive testing even has the potential to be used as an online monitoring tool in industrial applications.