Effects of enzymatic treatments on the mechanical properties of corn husk fibers

Corn husk fibers were extracted by water retting, alkalization, and enzymatic processes at different concentration and duration levels. The effects of extraction process parameters on the mechanical and thermal properties and chemical characteristics of corn husk fibers were investigated. Chemical structures of the fibers were studied by IR measurements. The finest and the stiffest fibers were produced by water retting followed by an enzymatic treatment. The highest breaking strength and breaking tenacity were obtained by water-retted fibers. While resulting in loss of breaking tenacity and elongation in water-retted fibers, enzymatic treatment resulted in increase in initial moduli and breaking tenacity of alkalized fibers. No significant effect of enzymatic treatment duration was obtained on the mechanical properties of corn husk fibers. Alkalized fibers gave higher elongation and lower stiffness compared to water-retted ones. The IR spectra showed higher amount of lignin and hemicellulose in water-retted fibers compared to alkalized and enzyme-treated ones. Enzymatic treatment and alkalization enhanced the thermal durability of the fibers. The ranges for properties of the produced corn husk fibers can be summarized as a linear density 17.0–25.6 tex, initial modulus 150.9–401.8 cN/tex, breaking tenacity 6.8–21.7 cN/tex, and elongation 9.6–18.2%.