Contents lists available at ScienceDirect Radiation Physics and Chemistry journal homepage: www.elsevier.com/locate/radphyschem Preparation of PVC/Bi 2 O 3 composites and their evaluation as low energy X- Ray radiation shielding A.G. Nuñez-Briones a , R. Benavides a,∗∗ , E. Mendoza-Mendoza a , M.E. Martínez-Pardo b , H. Carrasco-Abrego b , C. Kotzian c , F.R. Saucedo-Zendejo d , L.A. García-Cerda a,∗ a Centro de Investigación en Química Aplicada, Blvd. Enrique Reyna Hermosillo #140, C.P. 25294, Col. San José de los Cerritos, Saltillo, Coahuila, Mexico b Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Col. Escandón, C.P. 11801, México, DF, Mexico c Hospital Universitario de Saltillo, Calzada Francisco I. Madero #1291, Zona Centro, C.P. 25000, Saltillo, Coahuila, Mexico d Centro de Investigación en Matemáticas Aplicadas, Universidad Autónoma de Coahuila, Unidad Camporredondo Edificio “S”, C.P. 25115, Saltillo, Coahuila, Mexico ARTICLE INFO Keywords: PVC composites Bismuth oxide Radiation shielding ABSTRACT Plasticized and gamma crosslinked PVC composites were prepared by adding diferent amounts of Bi 2 O 3 par- ticles to evaluate their low energy X-ray radiation shielding properties. Composites were gamma-irradiated in an industrial irradiator ( 60 Co source) at the corresponding times to obtain a dose of 75 kGy to enhance mechanical properties through crosslinking. The shielding properties of composites were obtained by X-ray transmission measurements at low energies (X-ray tube voltages range 20–61 kV) by using a mammography unit and an X-ray hospital equipment. A small infuence in the dehydroclorination reaction of PVC was observed during decom- position in TGA experiments due to Bi 2 O 3 nanoparticle content, but DMA results show improved viscoelastic properties for the crosslinked composites. The X-ray transmission values decrease as a function of nanoparticle content, observing an increase in the transmission values (low attenuation) at higher energies. The composite with 50 %wt of Bi 2 O 3 showed the lowest transmission values, at X-ray tube voltages 20–30 kV, the transmittance was almost nil, and then it increases ~27% at 61 kV. 1. Introduction The X or gamma radiation shielding must meet certain requirements that are becoming stricter, considering the application of the ALARA principle (As Low As Reasonably Achievable) (Low and Azman, 2020). In medical diagnostic rooms, the shielding is based on the use of ma- terials made mainly of lead. However, in recent years there has been a major concern about the use of this material, because of its weight and toxicity (Aghamiri et al., 2011). Currently, many eforts have been made to develop new materials that are suitable for human protection exposed to radiation sources. As an alternative, the polymeric com- pounds, which are light, conformable and proftable, are suitable ma- terials that can be obtained for the efective attenuation of X-rays for use in medical diagnosis (Low and Azman, 2020; Nambiar, 2015). Materials in nanometric scale have attracted attention for the cur- rent materials science development, due to their fundamental and technological importance (Qiu et al., 2011; Bedoya Hincapie et al., 2012), being used in a wide variety of applications in various areas of knowledge such as electronic, aeronautic, medicine, nuclear science, etc. (Nambiar, 2015). The use of polymeric composite materials with nanometric fllings is a current strategy for the development of novel applications. Nanometric-sized fllings can be dispersed more evenly in a matrix with fewer clusters compared to micrometer-sized fllings (Noor Azman et al., 2013a). In recent years, several studies have been carried out to develop composite materials with a polymer matrix and loads in nanometric and micrometric sizes. Noor Azman et al., have carried out various studies on the production of epoxy resin compounds with diferent fllings, like Pb, Bi, W and WO 3 (Noor Azman et al., 2013a; 2013b). They used WO 3 in micro and nanometric sizes, fnding out that, at low energies, the particles in nanometric size have better attenuation properties (Noor Azman et al., 2013a). Furthermore, they also studied the attenuation of PLA/Bi 2 O 3 compounds with both particle sizes, fnding diferences in the X-rays attenuation according to the amount of particles used, as well (Noor Azman et al., 2013c). Shruti Nambiar et al., studied the use of PDMS/BO composite materials, fnding good attenuation results for 60 kV X-rays, with a load of 44.44 %wt for a sample thickness of 3.73 mm (Nambiar et al., 2013). Pavlenko et al., reported the https://doi.org/10.1016/j.radphyschem.2020.109198 Received 28 April 2020; Received in revised form 22 July 2020; Accepted 16 September 2020 ∗ Corresponding author. ∗∗ Corresponding author E-mail addresses: roberto.benavides@ciqa.edu.mx (R. Benavides), luis.garcia@ciqa.edu.mx (L.A. García-Cerda). Radiation Physics and Chemistry 179 (2021) 109198 Available online 19 September 2020 0969-806X/ © 2020 Elsevier Ltd. All rights reserved. T