Effect of gamma-rays on the thermal and mechanical properties of epoxy/tungsten boride composites

Abstract

High performance polymer composites are essential materials in nuclear applications where many components can receive high ionizing rays doses such as gamma-rays. In this work, two composites named E51WB and E51WB₂ based on epoxy (E51) and tungsten borides (WB and WB2) were manufactured at room temperature and then exposed to gammarays doses up to 2000 KGy. The goal of this study was to investigate and compare the impact of gamma-rays on the chemical structure, mechanical and thermal properties of E51WB and E51WB₂ composites using FTIR, SEM, TGA and tensile tests. As the results, the char yield (Yc) for E51WB gradually increased from 40 to 46% at 0, 1000 and 1500 KGy, then slightly drop to 44% at 2000 KGy. The E51WB sample displayed the strain value of 2.3% at 0 KGy, and it increased to 4.7 and 5 % at 1000 and 1500 KGy, respectively, while at 2000 KGy it decreased to 3.5%. This may be due to phenomena such as hydrogen abstraction, disproportion, degradation or the formation of new bonds. The comparison of the TGA results of E51WB and E51WB₂ at 1000 and 1500 KGy respectively, leads to the conclusion that E51WB₂ is thermally more resistant. In addition, by comparing the tensile strength of these two samples at the same irradiation doses, it can be stated that the E51WB₂ composite is stronger than its counterpart E51WB.