Adsorption of Ba(OH)2 on Mercerised Cotton Thread - Determination of Ba-number

Abstract

The method of determining Ba-number involves a few days work, ellimination of all the waste material from the cotton, extraction in organic solvent and boiling, then drying and Ba(OH)2 adsorption. Ba(OH)2 is conventionally done in Erlenmayer shaker, at room temperature, for two hours, by manual shaking of the vessel. The purpose of this investigation is to shorten the procedure of determining the Ba-number, wich has for all practical purpose been too long. Kinetics of Ba(OH)2 adsorption on cotton threads of 62.5 x 2 tex is investigated with this purpose in mind. The threads are mercerised in a wide range of concentration of NaOH, from 10 % to 30 %, with the adition of an anionic wetting agent. Ba-number is determined following the standard procedure first, then following the Edelstein method, by adsorption in the shaker, and finally in a Linitest laboratory apparatus. On the basis of Ba(OH)2, adsorption rates noted, the authors recommend shorter adsorption time for all procedures employed. Adsorption in shaker and in the Linitest apparatus is recommended for internal use, as a statistical analysis of the result obtained indicated significant differences in their arithmetical mean values, following the Student’s t-division.