Effect of alkaline pretreatment on the preparation of regenerated lignocellulose fibers from bamboo stem

In this study, the effect of alkaline pretreatment on preparation of regenerated lignocellulose fibers from bamboo stem was studied in detail. Prior to being dissolved in [Emim]OAc, bamboo stems were ground and treated with different concentrations of sodium hydroxide solutions. The obtained spinning dopes were then extruded into water coagulation bath and regenerated to composite fibers. The properties of the raw materials, spinning dopes, and regenerated fibers were investigated. Results showed that alkaline pretreatment could break the rigid structure of lignocelluloses by removing part of hemicelluloses and lignin as well as changing the polymorphous lattice and C _r I of cellulose. The increased specific surface area of raw materials enhanced the accessibility of solvent, promoted the swelling process and shortened the dissolution time. The viscosity of the spinning dopes and the strength of the regenerated fiber reached the maximum value when the bamboo powder was treated with 20 wt% sodium hydroxide at 60 °C for 4 h. In addition, the fibers prepared from the alkali-treated raw materials showed round cross-section and wrinkled surface. Therefore, the properties of the regenerated lignocellulose fibers could be improved by employing an appropriate alkali pretreatment of raw materials.