Development of a homogenisation approach to describe the mechanical behaviour of thermoplastic vulcanisates under consideration of the process-induced anisotropy

• Applicant: Professor Dr.-Ing. Christian Hopmann
• Subject Area: Polymeric and Biogenic Materials and Derived Composites ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 448100263

The demand for plastics with pronounced rubber-like properties is constantly increasing. For decades, these materials have included classic elastomers and, more recently, thermoplastic elastomers (TPE), which consist of a thermoplastic and elastomeric phase. In this way, the useful properties of elastomers are combined with the processing properties of thermoplastics.The group of thermoplastic vulcanisates (TPV) has a special role within the TPE. In TPV, the elastomer phase is cross-linked and finely dispersed in the continuous thermoplastic phase. Processing by injection moulding results in a processing-related phase morphology due to locally different orientation and dispersion processes. This leads to a highly pronounced anisotropy of the mechanical properties. In the literature, there are studies dealing with the relationship and modelling between morphological properties and mechanical behaviour. However, currently no adequate approaches available to consider the relationship between the direction-dependent material behaviour and the material composition. Therefore, this area can be called unexplored.The planned research project starts there. Preliminary investigations shows that the nonlinear material behaviour of TPE in flow direction can be mapped with good accuracy by extending existing hyperelastic material models. Unfortunately, this is only valid for an isotropic materials. By transferring the modelling approach to anisotropic materials, the nonlinear material behaviour is not adequately described. The aim of the project is to develop a homogenisation approach for describing the mechanical material behaviour of thermoplastic vulcanisates by taking into account the process-induced anisotropy with the aid of a representative volume element (RVE).

• DFG Programme: Research Grants