Developing the supertyre: the collaboration between Pirelli and the Department of Materials Science

Barbara Di Credico on Progettare

From a laboratory research activity on innovative and sustainable materials to the production on a large scale of a highly performing tyre. How? Thanks to the collaboration between the laboratory of Chemistry of Inorganic and Hybrid Materials, NanoMat@Lab, of the Department of Materials Science of the University of Milano-Bicocca and Pirelli Tyre S.p.A., as told by Barbara Di Credico, researcher in Principles of Chemistry for Technologies, on “Progettare”, the first Italian  magazine in the field of industrial production in a special edition dedicated to the automotive industry.

The research in the NanoMat@Lab has given rise to an advanced compound based on nanoparticles of natural silicate with specific morphological and surface characteristics. The application to the production on large scale gave rise to the SMARTNETTM Silica technology realized by the R&D group of Pirelli. This collaboration and the developed technology were awarded with the Innovation Grant 2018 Prize of Milano-Bicocca.

What are the still open challenges in tyre industry?

In tyre industry, the improvement of the mechanical properties, such as elasticity, traction and abrasion resistance, is obtained by dispersing in the rubber nanoparticles such as silica, and carbon black, which are reinforcing fillers - Dr. Barbara Di Credico explains. - In the increasing complexity of the current demands of the car manufacturers, the reinforcing materials have a fundamental role and the innovative fillers identification is a field of particular interest for the tyre industry to obtain high performing tyres.

The main innovative strategies in the field of tyre for the automotive aim at reducing the energetic consumption caused by the dissipation, associated to the rolling resistance, and simultaneously to improve the static mechanical properties and the abrasion resistance of the final product.

What was the contribution on research of the NanoMat@Lab team?

NanoMat@Labanisotropic inorganic oxides, having a high aspect ratio, of synthetic origins, i.e. the rod-like silica, and subsequently of natural origins like sepiolite, a mineral constituted of agglomerates of magnesium silicate fibers - Dr. Barbara Di Credico tells us. - The research has been focused on the investigation of the effects of structure, morphology and surface functionalization of the silica-based fillers on the dynamic-mechanical properties of rubber composites and afterwards on the production of compounds with the aim of obtaining new elastomeric materials and transferring the innovation and knowledge to the industry for the production of highly performing tyres. A controlled acid treatment enabled us to obtain sepiolite nanofibers of reduced dimensions and an increase of the superficial reactive groups, able to react with the rubber, but maintaining at the same time the crystallinity and the needle-shaped morphology.

Therefore, compounds having high reinforcement and at the same time low hysteresis were developed in a pre-industrial scale.

How was the research technological transfer realized?

The invention of new elastomeric compositions for tyres, including sepiolite nanofibers, was developed industrially in the Pirelli laboratories, being at the basis of SMARTNETTM Silica technology covered by 3 international patents related to applications from the tread to the structural compounds. SMARTNETTM Silica technology is based on sepiolite nanofibers which organize themselves in an ordered way inside the compound, creating a resistant structure and a long-lasting tyre, giving a low rolling resistance thanks to their natural anisotropic orientation, which reduces the heat increasing the elasticity to minimize the energy dissipation. Therefore, the employment of sepiolite in the tyre compounds has, not only a high impact on the tyre performances, but also the approach is eco-friendly and represents a strategic resource for the tyre development in the next decades.

How was the collaboration with Pirelli born?

The collaboration with Pirelli is part of the activities of Corimav, the Consortium for the Research on Advanced Materials, of which I coordinate the activities. Corimav was born in 2001 from the cooperation of Pirelli and the University of Milano-Bicocca, with the aim of developing novel technologies. In a long and virtuous path, which have lasted more than 20 years, Corimav has developed 18 patents, 44 scholarships and 46 phd scholarships in Materials Science and Technology. At the moment, Corimav funds every year three PhD scholarships, as well as specific projects aimed at turning the results of the research in products launched on the market with the aim of increasing the rate of innovation favoring at the same time the diffusion of increasingly eco-friendly solutions.

Nanomat@lab logo e Barbara Di Credico