Mechanical Properties of the Epoxy Resin Composites Modified by Nanofiller under Different Aging Conditions

And then, the mixture was put into a vacuum drying oven to remove bubbles. Afterward, in the curing process, a two-step curing process was used for a total of 5 hours, and then, the nanocomposites were cooled to room temperature.Neat EP and HNT/EP nanocomposites were soaked in deionized water at different temperatures (20°C, 40°C, and 60°C), HCl solution (5 wt.%) at 20°C, and NaOH solution (10 wt.%) at 20°C for 720 h.

These conditions are generally applied in some aging tests reported in previous studies .Sudden temperature changes of neat EP and HNT/EP nanocomposites from the hot chamber (100°C) for about 7 min to the cold chamber (0°C) for about 3 min were applied, and the thermal shock cycling (TSC) was repeated 100 cycles, which is similar to TSC test reported in previous studies .Composite aging conditions were combined soaking condition with TSC condition.

The samples are firstly soaked in deionized water, HCl solution, and NaOH solution at 20°C, and then, they are dried and employed in TSC for 100 repeated times.The tensile test is carried out by the universal material testing machine (MTS810, USA), and the test rate is 2 mm/min. Referring to GB/T2567-2008, the resin casting was machined in the appropriate size. To ensure the accuracy of the data, the experiment was repeated five times, and the calculated average value was used in this study.