ASTM D2959-95(2017)

Die Annotation des Normtextes ASTM D2959-95(2017) :

This test method covers the determination of ethylene oxide content in polyethoxylated nonionic surfactants. It can also be used for compounds containing propylene oxide or any compounds (glycols and glycol and polyglycol ethers and esters) which form unstable 1,2-diiodides on reaction with hydroiodic acid. The apparatus is comprised of the following: heat source which shall be an electric heater provided with a sliding rheostat or other means of heat control; flasks which shall be equipped with a standard ground-glass joint; condensers with standard joints; gas bubbler filled with dibutyl phthalate; buret; and pipet. The dual apparatus is designed to permit a sample and a blank to be run simultaneously. Reagent grade chemicals or reagents of sufficiently high purity including water, carbon dioxide or nitrogen, lubricant, dibutyl phthalate, glass beads, hydroiodic acid, hydrochloric acid, methanol, potassium dichromate, potassium iodide solution, sodium thiosulfate, and starch indicator solution shall be used in all tests. The ethylene oxide content shall be calculated from the amount of sodium thiosulfate solution required to titrate the sample and the blank, normality of sodium thiosulfate, and weight of the sample. Standard deviations for repeatability and reproducibility shall be estimated to determine the acceptability of the results.


Keywords:
ethylene oxide content, nonionic surfactants ,, ICS Number Code 71.100.40 (Surface active agents)