Experimental investigation and modelling of strain-induced crystallisation in natural rubber in different ageing conditions – SICX

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.