Differences in the hygroscopic behavior of bamboo fiber and parenchyma

The interaction between bamboo and moisture leads to mechanical properties and dimensional changes, which is an important issue affecting the processing and utilization of bamboo. Fibers and parenchyma cells are the main components of bamboo, and there are differences in hygroscopicity, but the main factors influencing the differences are unclear. Therefore, this study investigated the relationship between cells, chemical component content, pores and hygroscopic behavior of fibers and parenchyma cells, and analyzed the moisture types and the interaction of functional groups with moisture. The results showed that there was little difference in hygroscopicity between fibers and parenchyma cells at low relative humidity. At humidity greater than 60%, the difference in moisture absorption was significant. The maximum difference in moisture content between fibers and parenchyma cells was 8.81%. At low relative humidity, the abundance of pores did not show advantages, and the humidity had a greater effect on moisture content of parenchyma cells. In addition, moisture absorption at low relative humidity was selective, with moisture favorably bound to lignin. This study, by analyzing the differences in moisture types and absorption sites of fiber and parenchyma cell, could provide a better understanding of the binding mechanism between bamboo and moisture, to provide a theoretical basis for the subsequent research on hygroscopicity of bamboo.