Mixed radiation shielding via 3-layered polydimethylsiloxane rubber composite containing hexagonal boron nitride, boron (III) oxide, bismuth (III) oxide for each layer

In this study, silicone (polydimethylsiloxane) based 3-layered composite material containing hexagonal boron nitride, boron oxide and bismuth (III) oxide, respectively for each layer, was developed. Materials with boron content are effective in thermal neutron absorption so the composite of silicone rubber and hexagonal boron nitride(hBN) would be a good neutron shielding material. In addition, silicone rubber used in this study, is a high temperature vulcanization (HTV) type silicone rubber which is noted flexibility, high transparency and superior mechanical properties. Composite materials of 9 sets with different contents were prepared. Mechanical, thermal and neutron attenuation tests were performed. It was experimentally determined that a composite having lead equivalent thickness of 0.35 mmPb were developed. In addition, thermal neutron attenuation tests performed for each of 9 sets, and attenuation rates (I/I0) of between 69% and 71% was obtained and I/I0 value was drastically decreased to 30.8% with increase of hBN content from 10% to 30%.