Slaked Lime Solution as a Viable Eco-friendly Treatment to Improve the Tensile Strength of Maize Stem Fibers

Abstract

In this study, the effect of the environmentally friendly slaked lime solution on the tensile strength of maize stem fibers was investigated and compared with the tensile strength obtained with a 3% wt NaOH and 10% wt NaHCO3 solutions. Maize fibers from dried stems were manually extracted, cleaned, and treated with the respective three solutions at different soaking periods. The results showed that a maximum increase in tensile strength of 165.1% was obtained with the NaOH treatment (at 24 hours) followed by an increase of 107.1% (at 21 hours) for the Ca(OH)2, and a 46.6% (at 18 hours) increase for the NaHCO3 treatment. Analysis of the FTIR spectra revealed that the significant improvement in the tensile strength for the NaOH treatment is attributed to the partial transformation of cellulose I to cellulose II. However, the increase in the strength of the Ca(OH)2-treated fibers has been attributed first, to the significant reduction in the fiber cross-sectional area, second, to the removal of specific amorphous constituents such as hemicellulose, and to the formation of a stable calcium pectinate layer, which improves the fiber’s resistance to fracture.

Keywords

• maize stem fibers
• tensile strength
• sodium hydroxide
• sodium bicarbonate
• calcium pectinate
• slaked lime solution