Synthesis and characterization of nitrocellulose for potential application as propellant ingredient

Nitrocellulose (NC) has attracted interest amongst researchers due to its uses in a wide range of applications. However, its applications are dependent on the nitrogen content, with nitrogen content greater than 12.5%acceptable for propellant while less than 12.5% suitable for printing ink, varnishes, and paint There are various nitration methods to synthesize nitrocellulose, yet some of them have flaws, such as producing imstable nitrocellulose. As a result, this research focuses on producing highest amoimt of nitrocellulose using a mixture of sulphuric and nitric acids, so that it can be employed as a propellant ingredient The effects of nitrating parameters; mole ratio of sulphuric to nitric acids, etmperature and time were investigated to obtain the optimum parameters. Usually, traditional methods are employed to optimize parameters and product yields however, this mediod has drawbacks, such as the inability to interpret relationsbips between parameters and product yields as well as consumes more time to conduct more experiments. Therefore, Response Surface Method (RSM) is introduced in this work as a better optimization method (RSM). A
central composite design (CCD) was used to determine the optimum condition in synthesizing nitrocellulose. Hie optimum condition suggested by RSM were mole ratio H2SO4/HNO3 = 3:1 mol/mol; ternperature = 35®C; time = 22 min; %N = 12.55% (predicted value). When using RSM's advised conditions, the percentage of nitrogen content obtained in nitrocellulose was 12.64% (experimental value). RSM also displayed value of the residual standard error (RSE) was 0.71% which showed the good agreement with actual and predicted value. T^ee different cellulose sources; bacterial cellulose, kapok cellulose and commercialized cotton, were used to compare nitrocellulose that has high percentage of nitrogen content. Result showed bacterial nitrocellulose bad die highest nitrogen content (12.64%) in comparison with kapok nitrocellulose (12.23%) and commercialized cotton nitrocellulose (12.50%). It was then characterized by Carbon, Hydrogen and Nitrogen elemental analysis (CHN), Fourier Transform Infiared (FTIR), Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (X^), Thermal Gravimetric Analyser (TGA) and
Differential Thermal Gravimetric (DTG). In conclusion, bacterial cellulose is suitable raw material in producing nitrocellulose, which can be used for propellant application.