Determination of Ethylene Dimethacrylate (Ethylene Glycol Dimethacrylate) in Nitrocellulose-Base Propellants by Saponification, Bromination, and Infrared

摘要

Ethylene glycol dimethacrylate is determined in nitrocellulose-base propellants by saponification, bromination, and infrared. In the saponification method the ethylene dimethacrylate is saponified after extraction with methylene chloride. A slight correction should be made for the nitration products of diphenylamine which react with alkali. In the bromination method the ethylene dimethacrylate is determined by titration with potassium bromate after extraction with methylene chloride. A correction must be made for diphenylamine which is also brominated. Diphenylamine in propellants containing ethylene dimethacrylate must be determined after a steam distillation, using either the gravimetric of titrimetric bromination technique; it cannot be determined gravimetrically in the solvent extract because of interference by ethylene dimethacrylate. In the infrared method the ethylene dimethacrylate is extracted with methylene chloride and the ester peak at 5.78 microns is measured in the methylene chloride solution. The saponification, bromination, and infrared methods give approximately the same results. (Author)