CHEMICAL FINISHING OF COTTON .1. PREPARATION OF EASY CARE COTTON FABRIC WITH IMPROVED STRENGTH

Samples of cotton fabric were treated with either etherified methylola ted melamine (EMM), pre-polymerized EMM or their mixture with dimethyl ol dihydroxy ethylene urea (DMDHEU), in the absence and presence of Mg Cl2.6H2O as catalyst, by the pad-dry-cure method. Results obtained ind icated that the extents of the reactions occurring between EMM molecul es and the hydroxyl groups of cotton cellulose, as well as among thems elves (in situ polymerization), were significantly favoured at pH 2 an d/or in the presence of MgCl2 . 6H2O. Storing the treating solution to effect partial polymerization of EMM before commencing the treatment has an adverse effect on the magnitude of these reactions. The latter decreased also by increasing the DMDHEU ratio in EMM/DMDHEU binary mix ture. The opposite held true for the crease recovery. This contradicti on was interpreted in terms of the differences between the mode of rea ctions of the two finishing agents with cotton cellulose, that is, cro sslinking vis-a-vis in situ polymerization. Tensile strength and elong ation at break of the fabric decreased as the DMDHEU ratio increased, due to excessive fibre embrittlement caused by crosslinking.