Abstract
Quantitative estimation of purity of N-phenyl-ï¢-naphthylamine (Nonox-D) by electrophilic bromination method
Author(s): K.I.Dhabbe, S.Nandagopal, Mehilal, B.BhattacharyaN-Phenyl-ï¢-naphthylamine (Nonox-D) is used as an antioxidant in composite propellant formulations based on hydroxyl terminated polybutadiene (HTPB). The service performance of a composite propellant over a long storage period depends on the nature, effective concentration and purity of antioxidants added. Therefore, a new method has been developed to determine the quantitative estimation of purity ofNonox-D using bromate and bromide in acidic medium. The determination of quantitative estimation of purity involves treating Nonox-D with an excess of potassium bromate and potassium bromide in the presence hydrochloric acid using acetic acid asmedium.After bromination of Nonox-D, the excess bromine is quantitatively determined by addition of potassium iodide solution followed by back-titration of the liberated iodine with standard sodium thiosulphate solution. The data obtained by analyzing different sources of Nonox-D indicate that the developed method is much reliable, fast and accuracy tolerance is in the range of ±0.5% and more safe in comparision to toluene diisocyanate method reported earlier.
