Physico‐mechanical properties of gamma‐irradiated clay/polyester nanocomposites

In this study both uncalcined and calcined nanoclays (NC) were used as reinforcements for unsaturated polyester resin (UP).The nanoclay/unsaturated polyester composites (NC‐UP) were produced at various nanoclay contents (0, 3, 5, and 10 wt%) under the effect of two different doses of gamma rays 30 and 50 kGy. The mechanical and thermal properties of NC‐UP composites were studied. The compressive strength values of (NC‐UP) composites were found to increase with increasing the nanoclay content up to 5 wt%. Above 5 wt% of nanoclay, the compressive strength was decreased for the two different irradiation doses. Thermogravimetric analysis was carried out to determine the thermal stability and activation energy of the unsaturated polyester resin and its composites. The results also showed an enhancement in the thermal behavior of the composites with increasing nanoclay content. At a dose of 50 kGy, the addition of 5% nanoclay to unsaturated polyester increases the activation energy from 77 to 110 and 91 kJ/mol for uncalcined and calcined clay, respectively. The dispersion of nanoclay particles in polyester matrix was observed by scanning electron microscopy. The results clearly showed that, the calcination of the nanoclay content caused a desired effect on the final properties of NC‐UP composites as compared to the uncalcined nanocaly. The utilization of a higher gammairradiation dose (50 kGy) showed a good improvement in the thermal and mechanical properties as compared to the specimens irradiated at a dose of 30 kGy. The results are also confirmed by X‐ray diffraction analysis. POLYM. COMPOS., 39:3666–3675, 2018. © 2017 Society of Plastics Engineers