Closed Industrial Partnership Programme
|Title||'Understanding the visco-elasticity of elastomer-based nanocomposites' (VEC)|
|Executive organisational unit||BUW|
|Programme management||Prof.dr. D. Bonn|
|Partner(s)||SKF, Michelin, Dutch Polymer Institute|
Nanocomposites consisting of polymers reinforced with filler particles are important for a wide variety of industries and processes. Although these nanocomposites exhibit unique visco-elastic properties – and as such are widely applied in e.g. tires and sealings – the precise mechanism of the reinforcement is at best incompletely understood at present. The current proposal aims at understanding, and ultimately controlling, the macroscopic visco-elastic properties of such systems on the basis of both the microscopic intermolecular interactions and the mesoscopic structure of the composite. To this aim, we will (a) determine the structure across many length scales, (b) probe the interactions between the filler particles and the polymer matrix, and to (c) relate these to the measured macroscopic mechanical properties. Measuring and controlling the polymer-filler interactions will allow to construct detailed models for understanding the macroscopic mechanical properties of this important class of materials. The proposed primary project goal is to develop an improved understanding of the non-linear visco-elastic properties of reinforced rubber nanocomposites. The originality of the program is to combine efforts to apply several new and unique techniques like, for example, non-linear rheology, electron tomography, nanoindentation, vibrational sum frequency generation, and use the ensemble of these results in close collaboration with the modeling projects to develop reliable predictive models for future use.
Background, relevance and implementation
Polymer systems reinforced with filler particles constitute a huge market (several millions of metric tons/annum worldwide): examples include tires, many types of high performance plastics used e.g., in the automobile industry to replace steel, products for leisure and sports, and structural parts of advanced equipment. Probably the most widely used filler particle is still carbon black, used mainly in the tire industry. However nowadays the trend is towards 'green tires', and carbon black is progressively being replaced by silica filler particles. Such particles are both chemically and physically very different, and this change consequently calls for a rethinking of the existing know-how on polymer reinforcement by fillers, which has been obtained mostly through trial-and-error. Also, the silica system being much better controlled and characterized than the traditionally used carbon black system, it provides a unique opportunity to uncover the different physical processes behind the reinforcement.
It is here that this project aims to contribute. Despite their obvious importance, filler particle-polymer interactions have remained poorly understood, owing to lack of suitable theoretical and experimental approaches. The key issue that has remained unresolved is the exact mechanism of the reinforcement itself, which is the focus of this proposal.
One of the main off-spins will be to allow Michelin to manufacture 'greener' tires, SKF to manufacture better high-performance sealings, and the DPI community to profit from the obtained insights in the fundamentals of reinforcement with silica particles. Indeed, higher performance silica filled rubbers have already allowed reducing fuel consumption, manu-facturing waste and increasing tire lifetime. A more fundamental understanding of the mechanisms involved will surely help to go further in these directions.
In addition, results from this programme should find their way in the development of filled engineering polymers, notably low-Tg elastomer-based materials, with much improved properties.
The final evaluation of this programme consisted of a self-evaluation carried out by the programme leader in 2015.
Please find a research highlight that was achieved in 2013 within this FOM programme here.