Effect of Accelerated Aging on Bamboo Fiber Lunch Box and Correlation with Soil Burial Degradation

This study aimed to investigate the mechanical property decay that might occur during actual use and soil burial degradation of bamboo fiber lunch boxes. For this, the effects of three accelerated aging methods, namely damp-heat treatment, freeze-thaw cycle, and artificial weathering cycle, on the tensile strength, dynamic viscoelasticity, and chemical composition of bamboo fiber lunch boxes were compared, and a correlation of their mechanical property decay with soil burial degradation was established to obtain an acceleration factor (SAF) with aging time as a reference. The results showed that the mechanical properties of the bamboo fiber lunch box decreased to different degrees under the three accelerated methods, and the tensile strength decreased to less than 50% after 36 h of damp-heat treatment, 5 freeze-thaw cycles, and 11 artificial weathering cycles. However, after 10 days, the mechanical property of lunch box in soil degradation decreased by more than 50%. Infrared spectroscopy demonstrated rapid hemicellulose degradation during damp-heat treatment and freeze-thaw cycle, as well as a minor quantity of lignin, and a significant amount of lignin under artificial weathering cycle. With the freeze-thaw cycle and the artificial weathering cycle, the relative crystallinity dropped quickly, by 32.3% and 21.5%, respectively, but under damp-heat treatment, the crystallinity dropped barely, by 43.5%. The damage caused by the freeze-thaw cycle to the mechanical properties of bamboo fiber lunch boxes was greater than that by the damp-heat treatment and artificial weathering cycle. The fluctuation of SAF under freeze-thaw cycle was also more drastic. Compared to the artificial weathering cycle, the damp-heat treatment was more stable and reliable in predicting the decay law of soil burial degradation tensile strength of bamboo fiber lunch boxes.