Raffia hookeri Fiber: Effect of Alkali Treatment on Morphology, Composition and Technological Application Properties

Abstract

Background: The presence of natural fiber in composites has shown a positive influence on the resilience of the reinforced polymer composites but this influence shows variability with Natural fiber Surface treatment, concentration of treatment solution and the length of treatment time. 5wt.% of sodium hydroxide (NaOH) alkali solution concentration has shown to be effective and efficient in dissolving the hemicellulose and the lignin portions while preserving the cellulose part of the fiber. There is enough literature on the chemical, physical, mechanical and thermal properties of Natural fibers but there is no comprehensive study on the chemical composition, morphology and concentration of the chemical compositions, water absorption behavior and thermal properties of Raffia hookeri fibers. Objective: Given that these properties vary with both the plant type and Botanical species, we are taking this advantage to study in detailed the morphological and composition of Raffia hookeri fiber and to Characterize the fiber for the evaluation of Mechanical Properties for Technological application. Methods: Raffia hookeri fiber was extracted and the basic technological application properties such as moisture and water adsorption, morphology, chemical, physical and thermal properties were analyzed using, chemical composition analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), Fourier transformed Infrared (FTIR), X-ray diffraction (XRD) and Thermo gravimetric analysis (TGA) while tensile test was used to evaluate the mechanical behavior of the fibers. Results: Chemical analysis revealed that the fiber was made up of cellulose (40wt.%), hemicellulose (20wt.%), lignin (33wt.%) and extractives 7wt.%, Thermal analysis indicated thermal stability up to 220oC, while the SEM/EDS results revealed that the effect of treatment on the fiber surface increased with the treatment time and reached maximum after 10h. This variability inferred on the morphological composition which recorded modifying effects both on the fiber-polymer matrix and the mechanical properties of the treated fibers. The FT-IR and XRD results indicated modification of the functional groups on the fiber morphology which improved on the mechanical, moisture and water adsorption capacity of the treated fibers. Conclusion: The alkali treatment has modifying effects on Raffia hookeri fiber morphology and chemical composition which affect its technological application Properties.