Ethylene sulphate, hydrolysis

The observed reactivity sequence for aliphatic sulphonates closely resembles that for the corresponding aliphatic sulphates ethylene sulphate, trimethylene sulphate and dimethyl sulphate (12 1 6)127 for which S—O bond fission (14%) was again only observed for the hydrolysis of a five-membered cyclic sulphate. The heats of hydrolysis have, however, been measured for aliphatic sulphate esters and the existence of considerable ring strain in the five-membered system is indicated by the fact that the heat of hydrolysis of ethylene sulphate exceeds that of dimethyl sulphate by 5-6kcalmol-121. 

The resultant yellow sodium cellulose xanthate is dispersed in an aqueous caustic soda solution, where some hydrolysis occurs. This process is referred to as ripening and the solution as viscose . When the hydrolysis has proceeded sufficiently the solution it transferred to a hopper from which it emerges through a small slit on to a roller immersed in a tank of 10-15% sulphuric acid and 10-20% sodium sulphate at 35-40°C. The viscose is coagulated and by completion of the hydrolysis the cellulose is regenerated. The foil is subsequently washed, bleached, plasticised with ethylene glycol or glycerol and then dried. 

Singhal et al. [78, 79] have described a titrimetric method for the determination of low levels of Oxamyl residues in soils. Their investigations revealed that after hydrolysis Oxamyl gave a brown precipitate with carbon disulphide and an alkaline solution of copper(II) sulphate. This reaction suggested a procedure for the determination of Oxamyl by titration with ethylene diamine tetracetic acid of the copper remaining unreacted to the 1-(2 pyridylazo)-2-naphthol end-point indicator). The following stoichiometric reaction appeared to occur between Oxamyl and the reagents ... 

Other methods, states that the method can be used for ethoxylated alkanolamides. The method can be applied to the ethoxylates obtained by acid hydrolysis of alkylether sulphates and sulphated alkylphenol ethoxylates and subsequent extraction with chloroform or by deionisation. The chemical process is hydrolysis of the oxyethylene groups by nascent hydriodic acid, thermal decomposition of the ethylene di-iodide formed and titration of the iodine with thiosulphate. 

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