Baseline investigations of strength mechanism of hybrid material welds

混合材料，即所谓的聚合物共混物，被生产以联合收割机结合基本材料的优点，通过协同作用增强它们或调节化合物的某些性质。不同聚合物的混溶性仅在非常少的复合材料中是已知的。在不相容的聚合物的情况下，可以使用物理或化学增容剂来实现组分之间的边界层中的一定相容性。该研究项目的目的是将聚烯烃和聚酰胺焊接在一起，并了解其背后的强度机制。这两种聚合物作为原材料是不相容的，因此在焊接过程中不会产生足够的机械性能以用于技术应用。为了以积极的方式改变不相容性的条件，一个连接伙伴的材料在先前的模制过程中被化学改性。因此，马来酸酐作为增容剂通过反应性挤出结合到聚烯烃的大分子上。此外，增容剂允许不同聚合物的有限相容性。将反应性共混物焊接到未改性的聚合物的连接伙伴上，并且改变工艺参数以获得最佳的机械性能。研究工作包括热板焊接和振动焊接工艺。焊接工艺的选择是基于在连接阶段的热传递和流变条件的根本差异。在热板焊接中，连接区域通过热传导熔化，然后两个连接伙伴连接。在振动焊接过程中，摩擦加热和接合加热两个阶段同时发生。因此，在接合层中存在可以发现不同的共混条件的可能性。化合物和焊缝的机械和物理材料特性也将采用最先进的分析程序进行表征，以研究强度机制和形态。通过对所研究的混合材料焊缝的作用模式的广泛理解，可以将结果转移到其他材料组合。

Hybrid materials, so-called polymer blends, are produced to combine the advantages of the basic materials, to enforce them through synergies or to adjust certain properties of the compound. Miscibility of different polymers is only known for very few composite materials. In case of incompatible polymers physical or chemical compatibilizers can be used to achieve certain miscibility in the boundary layer between the components. The aim of the research project is to weld polyolefins and polyamide together and to understand the mechanism of strength behind. The two sorts of polymer are incompatible as raw materials and therefore do not develop sufficient mechanical properties during the welding process for technical applications. To change the condition of immiscibility in a positive way the material of one joining partner is chemically modified in a previous moulding process. Thereby maleic anhydride as compatibilizer is bounded to the macromolecules of the polyolefins by reactive extrusion. The compatibilizer allows a limited miscibility of the different polymers in addition. The reactive blends are welded to a joining partner of non-modified polymer and the process parameters are varied concerning optimal mechanical properties. The research work covers hot plate welding and vibration welding processes. The choice of the welding processes is based on the fundamental differences in heat transfer and in rheological conditions during the joining phase. In hot plate welding the joining area is melted by heat conduction and the two joining partners are joined afterwards. In vibration welding process the two phases of heating by friction und joining take place at the same time. Thereby it exists the potential that different conditions of blending can be found in the joining layer. Mechanical and physical material properties of the compounds and the welds as well will be characterized with state-of-the-art analytical procedures to investigate the strength mechanisms and the morphology. With broad understanding of the mode of action by the investigated hybrid material welds it is possible to transfer the results to other material combinations.