Emulsion xanthation of cotton and bagasse celluloses in presence of sodium and potassium hydroxides

Abstract

AbstractSodium hydroxide swelled cotton and bagasse celluloses to a greater extent than potassium hydroxide. Higher alkali concentration during xanthation favoured the dissolution of cellulose and the formation of the main sulphur byproducts. Compared to sodium hydroxide, potassium hydroxide resulted in lower dissolution of cellulose, higher degree of xanthation (γ‐number) of dissolved xanthate and greater formation of sulphur byproducts. The xanthation of the more open and accessible bagasse cellulose resulted in higher solubility, lower γ‐number of dissolved xanthate, and higher amounts of sulphide and thiocarbonate than in case of the more compact and less accessible cotton cellulose. Reducing the carbon disulphide ratio reduced the γ‐number of dissolved xanthate and the amounts of the main sulphur byproducts as well as the dissolution of cellulose. In case of xanthating cotton cellulose at the lower carbon disulphide ratio potassium hydroxide resulted in a lower γ‐number of dissolved xanthate than sodium hydroxide.