One-Step Processing and Bleaching of Mechanically Separated Kenaf Fibers: Effects on Physical and Chemical Properties

Abstract

Kenaf is an important bast fiber because it is biodegradable and has other ecofriendly characteristics. In this study, chelators, including ethylenediamine tetra acetic acid (EDTA) and citric acid (CA); surfactants, including phosphate ester (Silvatol), alkylaxylsulfonates (Conco), cationic quaternary amine (Atlas), and modified polyglycol ether (Tanapon); and bleaching enhancers, including sodium pyrophosphate, and sodium metasilicate, along with hydrogen peroxide bleaching, are evaluated for their efficiency in processing me chanically separated kenaf fibers. Treatment conditions, such as processing temperature, solution pH, processing time and chemical concentrations, are evaluated based on the resulting fiber strength and appearance. Gas chromatography and infrared spectroscopy are also used to study fiber chemical composition (syringyl and guaiacyl lignins) as affected by processing. The results indicate that the treatments can substantially remove lignin from bast fibers. The best whiteness and strength results are obtained with fibers processed with 5% sodium pyrophosphate + 5% Silvatol + 1.5% H2O2 at pH 10.5 and a temperature of 96°C for 60 minutes.