Fabrication of novel neutron shielding materials: Polypropylene composites containing colemanite, tincal and ulexite

Abstract

Exposure to neutron radiation can cause serious health problems, especially in nuclear power plants and their surroundings, high-flying aircrafts, and healthcare facilities. Conventionally, many neutron-shielding materials are used for protection, but their mechanical and thermal properties limit the use of these materials. Low density, low cost, and flexible neutron shields are becoming increasingly important for these uses, in particular where the weight factor, such as in the aerospace sector, is highly important. For this reason, polypropylene (PP) based composite materials were prepared and their neutron shielding features, such as effective removal cross-sections, half value layer, and mean free path were determined using GEANT4 code. The absorbed dose-measuring experiments were carried out using a241Am-9Be neutron source. Boron minerals such as colemanite, tincal, and ulexite were used in the production of the materials to reduce costs and increase neutron absorption capacity. All the results were compared with the shielding abilities of paraffin and conventional concrete. It was determined that these composites absorb neutron radiation much better than the referenced materials. Colemanite was characterized by X-ray diffraction (XRD) while PP was characterized by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). These composites prove to be valuable shielding materials for protection against neutron radiation in nuclear medicine, storage or transportation of radioactive waste, and other nuclear applications.