Predicting the Equilibrium Moisture Content of Moso Bamboo Based on Isothermal Sorption Curves

Moisture content critically affects the physical and mechanical performance of bamboo. To enable rapid prediction of the moisture content of Moso bamboo ( Phyllostachys edulis ), this study investigated the isothermal sorption behavior of three types of bamboo: untreated (UT), chemically modified (CT), and thermally modified (HT). Isothermal sorption tests were conducted at different relative humidity (RH) levels, and the effects of modification processes on hygroscopic behavior were analyzed. Five commonly used isothermal sorption models were evaluated for their applicability, among which the Hailwood–Horrobin (HH) model was identified as the most suitable for both untreated and modified bamboo. The model was further validated using recorded environmental conditions and measured moisture contents of bamboo splits. To account for oven-drying effects prior to sorption testing, correction coefficients of 1.24, 1.19, and 1.00 were introduced for UT, CT, and HT, respectively. Based on the corrected HH model, practical isothermal sorption curves were established for rapid prediction of the moisture content of untreated and modified Moso bamboo, providing a practical basis for engineering applications.