Projects / Programmes
Rheological behavior and mechanical properties for processing of highly filled powder – polymer systems
| Code |
Science |
Field |
Subfield |
| 2.13.00 |
Engineering sciences and technologies |
Process engineering |
|
| Code |
Science |
Field |
| T152 |
Technological sciences |
Composite materials |
| Code |
Science |
Field |
| 2.03 |
Engineering and Technology |
Mechanical engineering |
polymer metal composites, highly filled polymers, rheology, processing, modeling of flow
Researchers (10)
Organisations (2)
Abstract
Highly filled (HF) composites or concentrated suspensions are typically polymers with a large volume fraction of particulate fillers (inorganic or organic) that could be macro-, micro- or nano-sized particles. These particles could be of a wide variety of chemical composition, shapes, sizes and size distributions. They are generally aimed to impart specific properties of the polymer composite, which could include rheological, mechanical, dielectric, conducting, optical, luminescence, and other properties. Due to their versatility, HF composites are found in many industries, including automotive, additive manufacturing, biomedical, batteries, ceramics, composites, magnetics, electronics packaging, solid propellant, sand adhesives and others.
The processing of HF composites can be challenging, since high temperatures and shear rates are generally needed to process these materials and obtain the required structure. The filled molten polymers present nonlinear rheological behavior, such as wall slip, particle-binder segregation, swelling and surface instabilities. Several studies have been carried out concerning filled polymers, especially for low viscosity polymers (suspensions), however for high viscosity polymers the findings are often contradictory and mechanisms for their behavior are not well understood. At present there are also no mathematical models that could accurately predict the flow of molten HF composites, since the existing models do not consider stress rate dependency and particle loading on rheological behavior.
Therefore, the subject of our proposal is a systematic experimental study of individual components of HF composites and their effect on the rheological properties and processing, as well as on properties of solid HF composites. Moreover, the obtained experimental data will be used for development of improved flow models.
More specifically, the aim of this proposal is to find and identify mechanisms governing the rheological behavior of HF composites based on the properties of individual components. Identifying the governing mechanisms would enable the proper selection of individual components and processing conditions for better processability of HF composites leading to more homogeneous distribution of particles inside polymeric matrix and hence higher efficiency of final (mechanical and eventual functional) properties of such materials.
The properties of individual components, as well as the processing conditions, affect also the mechanical properties of solid HF composites. Thus, the second goal of the proposed project includes the investigation of the effect of individual components and their rheological properties (i.e flow behavior) during processing on mechanical properties of solid composites.
The third part of the project includes modeling of the flow behavior, since this enables obtaining an insight into the effects of individual properties of the components to the overall flow behavior of HF composites. In this part, the goal is to improve the existing models by including not only the volume fraction, occupied by the filler particles, and the maximum packing fraction, but also the processing parameters such as shear rate, temperature and pressure. The improved model will also take into account the particle-particle and matrix-particle interactions due to different surface characteristics of the filler particles.
In summary, the findings of the project will help with the understanding on how individual components of HF composites influence the rheological (flow) behavior and at the same time mechanical properties of solid composites. Improved flow models will enable more accurate prediction of flow behavior of HF polymers and thus the development of new or improved composite materials and manufacturing processes will be more reliable and faster.
Significance for science
Project goals:
- identify and understand mechanisms governing the rheological behavior of highly filled (HF) composites based on the characteristics of individual components
- identify the influence of the components on mechanical properties of HF solid composites
- improve the existing flow models (incorporating shear rate, temperature dependent viscosity and particle loading)
Due to the lack of knowledge in the field of HF composites, the project will make a significant contribution to the development of science:
1. Basic understanding of mechanisms governing the behavior of HF composites in molten state
Past research on rheology of HF composites has shown contradictory phenomena, since each individual component has a strong influence on the behavior of the whole system.
The use of systematic approach and extensive experimental data on the behavior of HF composites will allow to understand the basic mechanisms responsible for the flow of material. An explanation of the influence of the properties of particles, binders and additives, and process conditions on HF composites will be obtained.
2. Effect of the components on mechanical properties of solid HF composites
The composition of HF composites affects also the properties (mechanical) in solid state. An extensive experimental data, allowing to find mechanisms affecting the properties of solid HF composites, will be obtained.
3. Improved models for flow behavior of HF composites
Existing models don’t consider complex nature of the behavior of HF composites. The obtained experimental data will enable the upgrading of the existing models with consideration of flow behavior, volume fraction, maximum packing fraction and process conditions. The scientific field of rheology and HF polymers will obtain new modeling tool for accurate prediction of flow behavior of HF polymers, enabling the development of new or improved composite materials with better properties and optimized conditions for processing.
4. Dissemination of the results to students
The findings of the project will be presented and incorporated into the courses at the Faculties, seminars, practical work and diplomas. This will help to disseminate the obtained knowledge and understanding to young engineers and their future work.
5. Dissemination of the results to industry
HF composites are found in many industries (automotive, processing, biomedical, batteries, ceramics, …), where the results of the project will be of great interest and the fundamental knowledge will help at designing new products, processes and selecting proper processing conditions or just optimizing the existing ones. Project partners will transfer the obtained knowledge into industrial environment through personal contacts and by organizing seminars.
The results will be published in reputable scientific journals and at national and international conferences. Information and experimental results will be accessible to other researchers on the website after completion of the project.
Significance for the country
Project goals:
- identify and understand mechanisms governing the rheological behavior of highly filled (HF) composites based on the characteristics of individual components
- identify the influence of the components on mechanical properties of HF solid composites
- improve the existing flow models (incorporating shear rate, temperature dependent viscosity and particle loading)
Due to the lack of knowledge in the field of HF composites, the project will make a significant contribution to the development of science:
1. Basic understanding of mechanisms governing the behavior of HF composites in molten state
Past research on rheology of HF composites has shown contradictory phenomena, since each individual component has a strong influence on the behavior of the whole system.
The use of systematic approach and extensive experimental data on the behavior of HF composites will allow to understand the basic mechanisms responsible for the flow of material. An explanation of the influence of the properties of particles, binders and additives, and process conditions on HF composites will be obtained.
2. Effect of the components on mechanical properties of solid HF composites
The composition of HF composites affects also the properties (mechanical) in solid state. An extensive experimental data, allowing to find mechanisms affecting the properties of solid HF composites, will be obtained.
3. Improved models for flow behavior of HF composites
Existing models don’t consider complex nature of the behavior of HF composites. The obtained experimental data will enable the upgrading of the existing models with consideration of flow behavior, volume fraction, maximum packing fraction and process conditions. The scientific field of rheology and HF polymers will obtain new modeling tool for accurate prediction of flow behavior of HF polymers, enabling the development of new or improved composite materials with better properties and optimized conditions for processing.
4. Dissemination of the results to students
The findings of the project will be presented and incorporated into the courses at the Faculties, seminars, practical work and diplomas. This will help to disseminate the obtained knowledge and understanding to young engineers and their future work.
5. Dissemination of the results to industry
HF composites are found in many industries (automotive, processing, biomedical, batteries, ceramics, …), where the results of the project will be of great interest and the fundamental knowledge will help at designing new products, processes and selecting proper processing conditions or just optimizing the existing ones. Project partners will transfer the obtained knowledge into industrial environment through personal contacts and by organizing seminars.
The results will be published in reputable scientific journals and at national and international conferences. Information and experimental results will be accessible to other researchers on the website after completion of the project.
Most important scientific results
Interim report
Most important socioeconomically and culturally relevant results
