Thermal behaviour and structural features of chemically and bio-chemically modified jute substrate

Abstract

Effects of NaOH treatment, conventional hot H₂O₂ bleaching, H₂O₂ and K₂S₂O₈ combined room-temperature bleaching, mixed enzyme treatment and N-methylol resin finishing on thermal behaviour and structural features of jute substrate have been studied. Differential scanning calorimetric study under nitrogen cover reveals distinct peaks for thermal degradation of cellulose, hemicellulose and lignin components of chemically and bio-chemically modified jute, showing some positive or negative shifts of thermal degradation temperatures for each of the three major constituents of jute owing to alkaline / oxidative or enzymolytic degradation or resinification of the jute components. Thiourea formaldehyde (TUF)-resin treatment renders the jute substrate with maximum thermal stability. There is a measurable increase in the crystallinilty percentage for 1-5% NaOH treatment, and the same is decreased on oxidative or enzyme treatment and remains almost unaffected for AMF-resin or TUF-resin treatment. Observed chemical changes / interactions have been explained by the analysis of FTIR spectra and copper number of differently treated jute substrate. Higher copper number is observed for room-temperature bleaching than that for conventional H2O2 bleaching. Changes in the overall surface morphology of the treated fabrics have also been characterized by scanning electron microscopic study. Room-temperature bleaching followed by mixed enzyme treatment shows maximum surface cleanliness with a smooth and less hairy surface appearance. Both AMF-resin and TUF-resin treatments show a surface coverage with a resin film.