Exploring the simultaneous effect of nano‐silica reinforcement and electron‐beam irradiation on a model LDPE/EVA‐based TPE system

BACKGROUND: The technical properties of polyolefinic thermoplastic elastomer (TPE) systems can be modified significantly using fillers like nano‐silica. Controlled irradiation can potentially be an effective way of tailoring the technical properties of such nano‐silica‐filled TPE systems. RESULTS: The effect of controlled electron‐beam irradiation on the properties of a pristine silica nanoparticle‐filled model low‐density polyethylene/ethylene–(vinyl acetate) (LDPE/EVA) TPE system is explored in this paper. The morphology of such a filled system was investigated using scanning electron microscopy (SEM) and field‐emission SEM. The dispersion of silica particles was analysed using transmission electron microscopy which clearly indicates that at low loading a fine dispersion of silica occurs in the polymer matrix. Swelling studies and Fourier transform infrared analyses indicate the occurrence of a favourable EVA–silica interaction. On the whole, it is observed that electron‐beam irradiation induces a high degree of reinforcement in all the silica‐filled samples through interfacial crosslinking as well as controlled crosslinking in the two polymer phases. In a few samples the processing characteristics are remarkably preserved following concurrent nano‐silica reinforcement and irradiation, while the technical properties of TPE systems, including set, solvent swelling and mechanical properties, are improved. However, the improvement in properties is a strong function of sequence of addition of filler in the LDPE/EVA blends. CONCLUSION: The green technique studied can be potentially extended for the improvement of the technical properties of conventional TPE systems. Copyright © 2009 Society of Chemical Industry