Influence of drying temperature and duration on fiber properties of unbleached wheat straw pulp

Plant fibers are mainly composed of cellulose, lignin and hemicelluloses. Fiber swelling ability (water retention value) of unbleached wheat straw pulp and crystal structure of cellulose were studied for different drying temperature and duration. A low-temperature nitrogen adsorption method was employed to analyze the change of pore structure of the wheat straw fiber after drying. A transmission electron microscope (TEM) was used to characterize the change in the ultrastructure of fiber cell walls during drying. An increase of either variable (drying temperature or drying time) is harmful to the quality of the fiber, leads to a decrease in the swelling property of the pulps, the increases of crystallinity of cellulose and the lactones content, and to deformation and collapse of the fiber cell wall.