Novel composites made of natural and waste rubber loaded with lead nanoparticles for gamma radiation shielding

Abstract

A high-energy ball mill was used to prepare lead (Pb) nanoparticles (NPs) using polyvinyl chloride as a process control agent to prevent metal-to-metal contact and agglomeration. X-ray diffraction, transmission electron microscope, attenuated total reflectance–Fourier transform infrared and thermal gravimetric analysis were used to characterise the produced Pb NPs. The results show that Pb NPs are successfully prepared by high-energy ball milling with an average size of 32 nm. Pb NPs were added to natural rubber (NR)–waste rubber (WR) 50:50 blend. A good dispersion of Pb NPs in a polymer matrix is recorded with scanning electron microscope images. A composite containing bulk Pb was fabricated as a reference material. Both nano- and micro-composites were characterised for their mechanical and electrical properties and gamma ray shielding performance. The introduction of WR into an NR matrix decreased the tensile strength, the elastic modulus at 100% and the elongation at breakage but enhanced hardness, thermal stability, electrical conductivity and shielding parameters. Results further reveal that nano-composites show better improvement in the mechanical, electrical and shielding properties as compared to reference micro-composites.