Influence of alkaline delignification on moisture uptake behavior and bonding enthalpies of hemp

Raw hemp fibers are alkaline delignified to evaluate the effect of lignin on moisture uptake behavior hemp. Samples subjected absorption/desorption isotherms from 5% 95% relative humidity at three different temperatures (15, 25, and 35°C). The sorption ratio between untreated is lowered by 25%. Hysteresis makes evident greater influence binding low while high humidity, cellulose plays most important role. GAB, Hailwood-Horrobin Dent models fitted isotherms. Delignification temperature decrease size monolayer. energy constants monolayer differ according model used. Lignin causes great differences absorption desorption. is, lower constant. multilayer identical for models, showing a range variation in samples than samples. Based primary secondary constants, bonding enthalpies determined. Estimations desorption show higher correlation coefficients with which enables conclude that measures better explain delignification water