AMIDOXIMATION OF PARTIALLY CYANOETHYLATED COTTON FABRIC

Abstract

Researches on the amidoximation of N % 3_??_5 partially cyanoethylated cotton fabric with the aqueous NH2OH•HCl solution were carried out, including the effects of temperature and pH of reaction bath, concentration of NH2OH • HCl NH2OH/CN mol ratio and addition of nonionic surface active agent on the rate of amidoximation and the mechanical properties of the treated fabric. The results obtained are as following:For amidoximation, the neutral or minute alkaline solution of NH2OH and the temperature of 80°C and above are the necessary. The addition of nonionic active agent gives little retarding effect on the rate of amidoximation. Above and below about 15 of NH2OH/CN mol ratio, the relation of the first and the second order reaction is approximately applied respectively. The discolouration from pale blue to yellowish pale brown with the increase of the amidoximation takes place, while the discolouration of the lower amidoximation is small.By the amidoximation, especially the lower amidoximation of lower cyanoethylated cotton and the slower raising of reaction temperature, the crease and flex abrasion resistance as well as moisture regain increase considerably, retaining the most part of the tensile strength, elongation, tearing strength and softness of untreated fabrics. Generally, even the lower degree of amidoximation gives a striking increase of the acid dyestuff affinity and a great decrease of the basic dyestuff affinity. However, the affinity for the acid dyestuff “Eosine” is lost by the amidoximation.