Experimental investigation of the nonlinear quasi-static and dynamic mechanical behaviour of novel PA6/XHNBR thermoplastic vulcanizates: Linking mechanical nonlinearities to microstructural features

Abstract

Driven by the need to design environmentally friendly and sustainable polymeric materials that achieve superior mechanical properties, this work is centred on the relationship between the microstructure and the nonlinear quasi-static and dynamic mechanical behaviour of novel polyamide 6 (PA6)/carboxylated hydrogenated acrylonitrile butadiene rubber (XHNBR) thermoplastic vulcanizates (TPVs). In particular, with the aim to contribute to the further understanding of the physical mechanisms involved in the complex nonlinear mechanical behaviour of TPV compounds, the impact of different microstructural features of the PA6 matrix and the rubber network on the mechanical behaviour has been investigated. Interestingly, stronger rubber network interactions and so better elastic recovery capacity of the rubber network can hinder the growth of voids more efficiently. The observed micromechanical deformation processes are interpreted in terms of the role of the yielding, buckling and bending of thin PA6 ligaments at low strain levels and the rupture of covalent and non-covalent bonds presented in the rubber network at high strain levels.