Characterization of the corn husk fibre and improvement in its thermal stability by banana pseudostem sap

Abstract

An alkali based method has been optimised and proposed to extract the cellulosic fibres from the corn husks. Physicochemical and morphological properties of the fibres extracted from corn husk have been studied in detail, and compared with the well-explored cellulosic fibre, like cotton and ligno-cellulosic fibre, like jute. Scanning electron microscopy and energy dispersive X-ray were used to study the surface and cross-sectional morphology and the elemental analysis of the corn-husk fibres and compared with cotton and jute fibres. The analysis showed that the morphological and the physico-chemical properties of the extracted corn husk fibres are comparable with ligno-cellulosic jute fibre. Also, improvement in thermal stability of corn husk fibre was obtained by application of the agro-waste banana pseudostem sap (BPS). BPS treated corn husk fibre showed the limiting oxygen index (LOI) value of 32 against the LOI value of 21 for the control corn fibre. In vertical burning test BPS treated corn yarn showed self extinguishing behaviour and 50 mm char length whereas control corn yarn was burnt within 1 min with flame and afterglow. TG analysis of the BPS treated corn yarn showed more than 30% weight retention at 450 °C compared to the 20% weight retention of the control corn yarn at the said temperature. In addition, major mass loss peak in TG curve has been shifted from 350 to 300 °C after BPS treatment (signature of the dehydration effect of the treated corn yarn). The flame retardant treatment process is comparatively simple and cost-effective, as add-on remains only at 8% and the BPS is available in large quantity in many countries.