PROPOSALS FOR A ROUND ROBIN EVALUATION OF THE MOLECULAR MASS ANALYSIS OF NITROCELLULOSE EXTRACTED FROM PROPELLANT FORMULATIONS

摘要

Nitrocellulose is used as a principal component of a wide variety of propellant formulations. However, Service life assessments for these propellant formulations are commonly reliant on monitoring the remaining effective stabiliser content. This paper summarises the ongoing effort to develop a technique that can reliably assess the condition of nitrocellulose in propellant formulations. Nitrocellulose presents many challenges to the chemical analyst and STANAG 4178 (Edition 2) incorporates a non-mandatory size exclusion chromatography (SEC) method for determining the mean molecular masses (e.g. M_n, M_w) and a molar mass distribution. This SEC method was successfully evaluated by way of an International Round Robin test on four samples of pure nitrocellulose during 2009. A technique has been developed to extract nitrocellulose from propellant formulations for SEC analysis to determine the molecular mass. Nitrocellulose extracted from double and triple base propellant formulations is presented. It is now proposed that a second round robin will be performed to evaluate the repeatability and reproducibility of the extraction and subsequent molecular mass analysis. This paper describes the propellant nitrocellulose molecular mass analysis method in detail, presents results of a study performed by AWE and Cranfield University and concludes with objectives for the round robin test.