A Simulation Study about the Effects of Temperature on Compression Stress Relaxation for Natural Rubber (NR)

The model of natural rubber (NR) was constructed using molecular dynamics simulation to study the effects of temperature on compression stress relaxation. The solubility parameter and cohesive energy density clearly proved the three-dimensional periodic molecular model does be able to reproduce bulk experimental data of the authentic material. The motion of the molecular chain in the wide temperature range of 273-418 K was described by various structural analysis parameters. The mean square radius of gyration, mean square displacement (MSD) and fractional free volume (FFV) were investigated, all of which increased with the temperature rising up. Compression stress relaxation experiment was also conducted under different temperatures. It was found that the stress relaxation coefficient decreased as the aging time and temperature increased. The results showed that experiment and simulation were in good consistent.