Browsing by Author "Parker, Matthew"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    ItemOpen Access
    Solubility and chemical interaction of nitrocellulose in plasticisers
    (Cranfield University, 2016-11-07 09:10) Flood, Nathan; Parker, Matthew
    Technical paper presented at the 2016 Defence and Doctoral Symposium. Abstract: Nitrocellulose (NC) is commonly used as an energetic binder in explosive and propellant formulations. During the formulation and casting stages NC can be mixed with a variety of plasticisers with the aim of tuning the mechanical properties of the charge to suit the specified requirements. Historically there have been issues with the solubility of NC in various plasticisers which has created manufacturing problems leading to failures of missiles.The research presented from two programmes of work funded by the WSTC, Propellant Bonding and Nitrocellulose: Degrees of Freedom, has investigated how NC interacts with three plasticisers; Triacetin (TA), Diallyl Phthalate (DAP) and Nitroglycerine (NG). The solubility was investigated using time-lapse microscopy and the chemical interaction was investigated using Attenuated Total Reflectance Infrared Spectroscopy (ATR-FT-IR) and compared with the five modes describing the swelling and dissolution mechanisms of wood and cellulose fibres.The mechanisms observed for nitrocellulose follow the dissolution modes described for wood and cotton fibres. It was found that TA had the highest solubility with respect to NC whilst NG had the lowest; variation in the swelling and gelation of NC has been rationalised by the crystallinity within the sample. Changes in the cellulosic fibrillar substructure of NC due to nitration and processing results in changes in its crystallinity. This variation of crystallinity subsequently affects the chemical interactions of solvent and plasticiser molecules with NC and the bulk movement of these molecules through the material. ATR-FT-IR demonstrates the presence of constructive bonding interactions between NC and TA or DAP, which manifests as swelling and gelation at the bulk-level. NG exhibits no apparent molecular bonding by IR measurement, and sorption only into the NC fibre, without the extensive swelling and gelation observed in the other regimes.    
  • Thumbnail Image
    ItemOpen Access
    Stability and hazard properties of improvised nitrocellulose
    (Taylor & Francis, 2023-02-12) Moniruzzaman, Mohammed; Houlihan, Emma; Parker, Matthew; Wilson, Ian
    Nitrocellulose is a vulnerable and sensitive energetic material that can easily be manufactured from ordinary household chemicals and used for illicit purposes. Hazards of this material can lead to incidents resulting from unplanned initiation in manufacturing, storage or handling. Thermal stability and hazard data for so-called improvised nitrocellulose (IN) are crucial to formulate guidance for storage and handling of such materials recovered from illegal possession. This study focused on the energy content, stability and safety properties of IN. The energy contents increase linearly with nitrogen contents of IN. Improvised nitrocellulose showed a similar sensitivity to impact and electrostatic discharge, but vacuum stability testing demonstrated more gas release (2.8–3.4 cm3 g−1) compared to commercial NC (1.7 cm3 g−1). Chemiluminescence analysis established activation energies for hydrolytic and thermolytic decomposition to be 36 and ~93 kJ mol-1, respectively. Results suggest that NC samples recovered from improvised devices or illegal possession should be handled with special care.