Modifications of Alfa fibers by alkali and hydrothermal treatment

Moroccan Alfa plant (Stipatenacissima L) was investigated using several techniques: chemical composition, Fourier transform infrared (FTIR), crystallinity index determined by X-ray diffraction and scanning electron microscope (SEM). The raw fiber contained 39.53wt% of cellulose, 27.63wt% of hemicellulose, and 19.53wt% of lignin. The longitudinal view by SEM confirmed the bundle shape. Moreover, a homogeneous distribution of various particles called trichomes with regular forms was recorded. The aim of the research is to improve the properties of Alfa fibers via a mild and effective technique in order to proceed their utilization in construction. To modify the surface, fibers were treated by sodium hydroxide (6wt%) and hydrothermal treatment at different times. A comparison was carried on the untreated and treated Alfa fibers by several techniques. Enhanced properties were obtained with 6h of treatment by sodium hydroxide and 1h by hydrothermal treatment. Both treatments exhibit a modification of the fibers microstructure and morphology; FTIR and chemical analysis confirmed the hemicellulose and lignin reduction after 6h of alkali treatment and 1h of hydrothermal treatment. As a result, an improvement of the crystallinity index was noticed. SEM micrographs also confirmed an enhancement of the fibers roughness after treatment. [GRAPHICS] .