Chemical Modification of Jute Fabric with Ethylene Glycol and its Mixtures with Glyoxal and Aminosilicone Com- pound Under Different Catalyst Systems for Improving its Textile Related Properties and Thermal Behaviour

摘要

Raw / bleached jute fabric was subjected to (a) controlled/ limited oxidation using K2S2O8 and NaIO4 pretreatment to produce oxy-jute substrate and subsequently to (b) treatment with ethylene glycol under two different catalyst system {MgCl2 or Al2(SO4)3} following pad-cure (thermal treatment) technique for improving its textile related properties and thermal behaviour. Between NaIO4 and K2S2O8 as oxidizing agent, NaIO4 is much stronger and causes damages to the fiber, while K2S2O8 pretreatment followed by a short UV-light exposure is found to be milder but advantageous for subsequent modification of the oxy-jute substrate with ethylene glycol. The proposed reaction mechanism is also supported from FTIR and DSC analyses. Changes in important textile related properties for modification of the oxy-jute substrate under different conditions of treatment have been investigated and based on the observed results; all the reaction parameters have been optimized. The optimized reaction conditions found are: K2S2O8 - 0.5% owf, time of UV-light exposure after the K2S2O8 treatment-15 min, concentration of ethylene glycol - 8% owf, concentration ofAl2 (SO4)3 - 5% owf, curing temperature - 130°C and curing time -10 min. The 0.5% K2S2O8 pretreated oxy-jute substrate was also modified with different proportions of mixtures of ethylene glycol and aminosilicone and also with mixtures of ethylene glycol and glyoxal. Treatment with the overall 8% (owf) dose of application for a 30:70 ratio of mixture of ethylene glycol and aminosilicone to the K2S2O8 pretreated oxy-jute fabric renders the fabric a higher weight gain and crease recovery angle along with increased thermal stability, but also with marginally higher tenacity loss. Use of glyoxal in any proportion in the mixture of ethylene glycol and glyoxal for such chemical modification does not produce any property advantages and causes much higher loss in tenacity. Most of the said chemical modifications except the initial K2S2O8 pretreatment show some increase in crystallinity percentage due to positive alteration of apparent orientational effect owing to some crosslink formed by the said modifications. Study of surface morphology of differently modified bleached jute fabric reveals that application of 30:70 ratio of mixture of ethylene glycol and aminosilicone on oxy-jute fabric renders it much uniform and smooth cover of polymeric film suppressing the surface etching and damages occurred in initial K2S2O8 oxidative treatment.