2024 Volume 13 Issue 2 Pages 88-
Lead (Pb) have often been used as radiation shielding materials in various fields, including the aerospace and medical fields together with nuclear power plants. However, lead has several disadvantages. As the replacement, the composites, consisting of barium or bismuth having high atomic number and rubber or resin as the matrix, have been reported. In this research, we prepared the composites using barium sulfate and biodegradable polymer, consisting of glycerol and tapioca starch. The mechanical properties, such as softness and strength, controlled by optimizing the three-component materials, which will be presented together with X-ray shielding properties. In our previous study 1) , the effect of the inorganic filler surface modification on the mechanical property was shown. Here, we proposed a biodegradable additive, Tannic Acid (TA), as a new approach for the surface modification and its effect will be presented. Barium sulfate (BaSO4), having the particle diameter of 10μm, was used. Glycerol is a liquid component to make thermal processability for Tapioca-starch. In addition, Tannic acid (TA) was used for surface modification between matrix and BaSO4. Samples was produced using bath-type melt mixing at 120℃and 30rpm for 10min. The mechanical properties of the biodegradable composites, consisting of glycerol and tapioca-starch, suggested that the composites are very soft due to low tensile strength, modulus and high strain. By the addition of BaSO4 30vol%, the mechanical property of the composites was dramatically improved. On the other hand, TA coated BaSO4 made the elongation at break larger, which can be interpreted by the effect of hydrogen bond between the matrix and surface. The present finding demonstrated that this proposed approach using TA as the surface modification will be one of the most effective and attractive approaches to enhance the flexibility of radiation shielding composite materials including large amount of inorganic filler particles.
