Investigation of gamma radiation effect on mechanical properties of nanoclay added composite plates

Composite materials are widely used as an alternative to traditional materials with the developing technology. In order to improve the performance and mechanical properties of composite materials in the areas where they are used, nanocomposite materials are produced by adding nanoparticles into epoxy resin. In particular, the environmental conditions that composites/nanocomposites are exposed to are effective on mechanical properties. These environmental conditions are often encountered as water, humidity, temperature, radiation, etc. In this study, glass fiber reinforced epoxy composite samples with no additives and nano clay additives were produced. The effect of gamma radiation on the mechanical properties of these samples was investigated experimentally. Nanoclay was used as the nano material in this study. Nanoclay ratios were determined as 0.75%, 1% and 1.25% according to the epoxy resin weight. Nanoclay additive glass fiber reinforced composite plates were produced according to these ratios. The production of 8-layer and 2.1 mm thick plates was carried out by hand lay-up method. Both the prepared composites with and without nanoclay additives were exposed to irradiation at 10 kGy and 20 kGy doses at 1.75 irradiation rate by Co 60 irradiation source. Then, these samples were tested to determine their mechanical properties. As a result of the experiments, it was determined that the tensile, compression, shear strength, elasticity and shear modulus values of the 1.25% nanoclay additive glass fiber reinforced epoxy composite samples that were not exposed to gamma radiation were 2.5%, 14.69%, 11.6%, 5.7%, 24.7% higher than the values of the undoped samples that were not exposed to gamma radiation, respectively. The tensile, compressive, shear strengths, elasticity and shear modulus values of the 1.25% clay added samples exposed to 20 kGy gamma radiation were found to be 1.6%, 16.68%, 4.48%, 6.1%, and 43.7% higher than the values of the samples without clay added exposed to 20 kGy gamma radiation, respectively. It was found that the tensile, compressive, shear strengths, elasticity and shear modulus values of the 1.25% nano clay added samples exposed to 20 kGy gamma radiation were 0.93%, 1.46%, 10.01%, 0.60%, and 3.85% lower than the values obtained when exposed to 10 kGy gamma dose. However, it was observed that the gamma radiation dose did not affect the Poisson ratio. We believe that the obtained results will contribute to the literature and its use in application areas. Key words: Gamma radiation, Composite material, Nanoclay, Nanocomposite material