Comparative evaluation of two bleaching solutions on Kenaf fiber-reinforced nylon: Surface properties and FTIR analysis

3D printing has revolutionized various industries as well as enriching different important sectors including medicine and dentistry. Fused Deposition Modeling (FDM) is one of the significant techniques for 3D printing which utilizes thermoplastic filament feedstock. Natural fibers have been integrated into composite filament to enhance mechanical and physical defects of the FDM printed materials. The aim of this study was to assess the impact of two types of chemical treatments on kenaf fibers reinforcing polyamide composite filament by evaluating their chemical and surface properties. Sodium hydroxide (NaOH) and sodium hypochlorite (NaOCl) were the two chemical treatment solutions where kenaf fibers was processed at 6% concentration of each solution. Then, the fibers were compounded with nylon beads to form FDM filaments. Three groups of specimens were printed by FDM printer which were control, NaOH-treated, and NaOCl-treated. The samples were characterized by FTIR and evaluated for their surface hardness and surface roughness. The FTIR results showed that NaOH treatment was not as effective as NaOCl treatment in terms of eliminating lignin and hemicellulose. Surface hardness and surface roughness demonstrated minor improvement for the NaOCl-treated group compared to NaOH-treated group. It is recommended to rely on NaOCl treatment at 6% concentration with treatment time not exceeding 24 hours.