Strain-induced crystallisation (SIC) in natural rubber is at the origin of its outstanding performances such as self-reinforcement and resistance to failure. The SICX project has several objectives: First, it aims to provide a comprehensive set of data describing the kinetic evolution of the microstructure associated with SIC and its impact on the macroscopic mechanical properties, specifically self-reinforcement, which are both not yet decrypted. Secondly, these data will enable developing 3D modelling based on identified physical mechanisms and suitable for being implemented in a FEM code. Thirdly, ageing in complex thermomechanical environments, under air and solvent exposure, and its interactions with SIC, will be studied experimentally and finally modelled. Identifying the main physical ageing mechanisms in real-life conditions is a major scientific challenge as it is essential to extend the life of key industrial materials. To this aim, the SICX project will combine advanced physical characterisation by real-time X-ray diffraction during tensile tests, by electron microscopy and by NMR (France), ageing tests in well-controlled operating conditions and advanced thermomechanical 3D modelling (Germany). All partners have many years of experience in their respective fields and will combine their approaches from polymer physics and material modelling.

The factory of the future must ensure flexible, reliable and efficient production. For the production of silicone parts, widely used in industry, current processes based on molding and injection techniques do not meet these requirements. Additive manufacturing (AM) should overcome these problems. However, the rheological behavior of silicone as a flexible material during deposition is complex and difficult to model. Conventional additive manufacturing strategies, using deposition strategies which are adjusted off-line with a priori knowledge models, find their limits. In the RAMSAI project, we propose to develop a new approach to AM by exploiting artificial intelligence to control the rheological behavior of silicone during extrusion. The work will be multidisciplinary, combining material science, mechatronics, artificial intelligence, and robotics. A new silicone printing head integrating rheological control of the silicone and dimensional control of the filament will be developed. The closed-loop control of silicone rheological behavior will use physics-based machine learning and predictive algorithms. The filament dimensions will be controlled using a variable shape nozzle already developed by the project partners. For complex parts, the contribution of a control of the print head in position and orientation using a robotic arm will be determined. These scientific and technological developments will lead to the realization of demonstrators which will highlight the new performances of the process. The first application area targeted will be health care, with a proven need today for tools to produce patient-specific realistic anatomical models for training and planning surgical interventions.

Every year, crops are attacked by dangerous pest species, resulting in significant economic losses and risks. Aphids, for example, are among the most damaging taxa. Their control is challenging because of their specific feeding behaviour and unusual reproductive biology. Current control strategies, based on extensive use of chemicals, are considered unsustainable for sustainable agriculture due to the negative impacts on the environment and human health. Moreover, this approach has led to increasing insect resistance to pesticides. Therefore, there is a need for new solutions for pest control. The French national "EcoPhyto" plans and the "Farm to Fork" strategy of the European Greendeal have the common goal of reducing and replacing pesticides and promoting new solutions for sustainable agriculture. In recent years, alternatives to reduce the use of chemicals and pesticides have been developed through the development of physical barriers, such as the use of insect nets, which are mainly made of high-density polyethylene. However, this is a palliative measure that involves the disposal of such waste materials. Since such polymeric materials are often placed on plants and sometimes buried in the ground, it is troublesome to collect them separately from plant debris and soil. They must then be stored for at least three years, until the amount of chemicals and pesticides has decreased, before they can be recycled at low cost. Currently, European countries are encouraging the industry to rethink its production methods to reduce the use of fossil resources and minimise the environmental impact of products throughout their life cycle. For these reasons, new French and European regulations, as well as environmental issues such as plastic pollution, pose a real challenge to the development of new bio-based and/or compostable materials for different market segments. As a result, bio-based materials are on the rise, mainly based on plant components, i.e. from annually renewable sources (sugar cane, corn, oils, etc.). However, these bio-based materials do not have suitable properties to be easily processed and suitable for applications that require combined performances such as specific mechanical properties and additional functions such as insect repellency. Biobased textile fibres today are mostly based on polylactic acid (PLA) due to its rheological and melting properties. Natureworks' Ingeo® fibre, for example, is well known for apparel (socks), furniture (bedding) and technical applications (roofing and geotextiles). However, the mechanical properties of PLA fibres drastically limit their potential for use in technical textiles compared to fossil-based polyethylene fibres, which can achieve high strength values. Therefore, the challenge of the BIO_III project is to overcome these limitations by developing biodegradable and bio-based textile fibres that exhibit multifunctionality, i.e., high strength and insect repellency. Due to their bio-based and biodegradable nature, PLA and then polybutylene succinate adipate are being considered as they are certified as "OK compost" and "OK compost HOME" respectively. In this way, polyester-based fibres are going to be processed into knitted fabrics that have an excellent surface-to-volume ratio and allow the release of natural molecules. To address these two challenges, a new generation of bio-based and biodegradable polymers is being developed that contain bio-insect repellents derived from the fraction of sweet potato aerials parts containing caffeic acid compounds.

HIPPOPOTAME aims at establishing simple and general routes to design industrially-relevant thermosets with extended lifetime through mechanical reinforcement induced by organization of block copolymers as vesicles and more particularly as wormlike micelles in epoxy networks. To do so, HIPPOPOTAME will rely on an original approach combining Polymerization-Induced Self-Assembly in reactive media (RAFT PISA in epoxy precursors) and supramolecular chemistry (H-bonding stickers) to precisely control the block copolymer morphology and the inclusion of sacrificial bonds. The newly designed cross-linked networks will exhibit an improved damage tolerance without any noticeable plasticization.

Lubricating oils are being increasingly used across several industrial applications and the demand for these materials is on the rise and is expected to grow further in order to reduce machinery energy consumption and wear. Within this framework, the development of high performance lubricants is the key for the expansion of important industries and markets. Recently ionic liquids (ILs) have been shown to be promising candidates for novel high performances lubricants thanks to their various physico-chemical properties and their ability to lower significantly the friction between two surfaces. Such promising properties of ILs were found to be highly related to their capacity to nanostructure in bulk and at interfaces. However, the range of viscosities available in most IL classes is rather narrow compared to macromolecular lubricants. Poly(ionic liquid)s (PILs) are thus promising candidates to translate the frictional and chemical properties of both polymers and ILs to innovative and highly tuneable macromolecular lubricants. The addition of local interactions inherited from ILs to macromolecules results in a complex and rich panel of chemical and physical properties opening new opportunities to design polymeric materials with targeted functions which are highly related to both structural and dynamical properties of PILs. The POILLU project aims to take advantage of the lubrication properties of ILs and strong slippage ability of polymer melts to develop PILs with enhanced lubrication properties. Supported by the synthesis of a new class of tailored PILs specifically designed to meet the stringent criteria and ambitious objectives of this the project, this multidisciplinary consortium will perform a detailed molecular description of the bulk and interfacial stress transmission mechanisms involved in PILs using complementary state-of-the-art experimental techniques mastered by skilled soft matter physicists. The coupling of extensive bulk rheological characterization and advanced scattering techniques (SANS, WAXS) will enable us to determine the multi-scale structure/dynamic relationship occurring in PILs. The enhanced interfacial nano-structuration of PILs and its impact on surface chains dynamics will be studied thanks to Grazing Incident X-ray Scattering and Surface Force Apparatus nano-rheological measurements. Finally, the lubrication properties of PILs will be characterized using photobleaching based velocimetry technique. This interdisciplinary approach gathering internationally renowned skills in polymer chemistry, physical chemistry and physics that will highlight the exotic properties of PILs both in bulk and at interfaces opening appealing scientific perspectives in the field of complex polymeric materials targeting specific function through a multiscale molecular design.