Cavitation in thermoplastic-reinforced rubber composites upon cyclic testing: Multiscale characterization and modelling

During their application, rubber composites exhibited cavitation upon deformation, being at the origin of the material breakdown. In this paper, a multiscale approach was proposed to study cavitation mechanisms in a solution styrene-butadiene rubber (SBR) composite reinforced with ultra-high molecular weight polyethylene (UHMWPE) micro-particles. Cavitation was characterized upon tension by 3D digital image correlation (3D-DIC), micro-computed X-ray tomography (mu CT), and scanning electron microscopy (SEM). The main results indicate that cavitation resulted from UHMWPE particles-SBR matrix debonding at UHMWPE poles, this mechanism being enhanced between neighboring UHMWPE particles. The cavities formed, grew and coalesced, resulting in cracks propagating perpendicular to the loading direction. The estimated volume strain was linked to mixing and curing conditions dictating the UHMWPE-SBR interfacial adhesion (the higher the adhesion, the lower was the volume strain). Besides, the ageing of materials conducted to a deterioration of the interfacial adhesion enhancing volume strain. An empirical model was proposed to predict the volume strain of the materials, exhibiting a good correlation with the experimental measurements.