Effect of chemical extraction parameters on corn husk fibres characteristics

Abstract

Corn husk fibres have been extracted by alkalization process at different alkali concentrations and treatment durations. The effects of extraction process parameters on the physical properties, mechanical properties and thermal durability characteristics of corn husk fibres are investigated. Chemical structures of the fibres are studied by infrared spectroscopy measurements. The average length, linear density and moisture content of extracted fibres decrease with the increase in alkaline concentration and duration. Breaking force decreases with increased alkaline concentrations. Increasing treatment duration for all concentration levels increases the breaking force, tenacity and initial modulus up to a point and then decreases them with further increase in duration. The highest tensile performance could be obtained from 5-10 g/L NaOH treatment for 60-90 min. Alkalization under harsher conditions results in higher thermal durability up to 320°C with higher cellulose fraction, but lower durability above this temperature. The FTIR spectrum analysis proves higher cellulose but lower hemicellulose and lignin contents with harsher treatment conditions. The marginal effect of concentration decreases for higher concentrations which suggests that the available sites for chemical reaction are occupied at moderate concentrations.