X-ray attenuation and mechanical properties of tungsten-silicone rubber nanocomposites

In this study, by using tungsten nanoparticles as filler and RTV silicon rubber (SR) as the matrix, thick flexible highly loaded composites were fabricated (up to 80 wt%). Interestingly, by incorporation of W particles in SR, the tensile strength of composites improved by average, e.g. 45% augmentation in 80 wt%. The young modulus was increased as well, e.g. from 0.38 MPa in the pure polymer to 1.10 MPa in 80 wt% composite. Experimental results showed that, the absorption of x-ray increases considerably by increasing tungsten proportion of samples. For example, the mass attenuation coefficient of 59.5 keV x-ray grows from 0.20 cm² g⁻¹ in the pure polymer to 2.32 cm² g⁻¹ in 80 wt%. Moreover, the attenuation process is simulated by a Monte Carlo code (MCNP4C) and the results compared with the experimental data as well as XCOM database. The simulation results were in good agreement with the experimental results, confirming homogeneous dispersion of the particles in the matrix. The preservation of flexibility, increase in tensile strength, and comparable mass attenuation relative to the lead-based attenuator, make these composite to be attractive for radiological protection, in particular when the photons have higher energy than the tungsten x-ray adsorption edged, i.e. 69.5 keV. (paper)