Composite propellants are composed of a solid oxidizer that is mixed into a
hydrocarbon binder that when polymerized results in a solid mass capable of selfsustained
combustion after ignition. Plateau propellants exhibit burning rate curves that
do not follow the typical linear relationship between burning rate and pressure when
plotted on a log-log scale, and because of this deviation their burning behavior is
classified as anomalous burning. It is not unusual for solid-particle additives to be added
to propellants in order to enhance burning rate or other properties. However, the effect of
nano-size solid additives in these propellants is not fully understood or agreed upon
within the research community. The current project set out to explore what possible
variables were creating this result and to explore new additives.
This thesis contains a literature review chronicling the last half-century of
research to better understand the mechanisms that govern anomalous burning and to
shed light on current research into plateau and related propellants. In addition to the
review, a series of experiments investigating the use of nanoscale TiO2-based additives
in AP-HTPB composite propellants was performed. The baseline propellant consisted of either 70% or 80% monomodal AP (223 μm) and 30% or 20% binder composed of
IPDI-cured HTPB with Tepanol. Propellants’ burning rates were tested using a strand
bomb between 500 and 2500 psi (34.0-170.1 atm).
Analysis of the burning rate data shows that the crystal phase and synthesis
method of the TiO2 additive are influential to plateau tailoring and to the apparent
effectiveness of the additive in altering the burning rate of the composite propellant.
Some of the discrepancy in the literature regarding the effectiveness of TiO2 as a
tailoring additive may be due to differences in how the additive was produced. Doping
the TiO2 with small amounts of metallic elements (Al, Fe, or Gd) showed additional
effects on the burning rate that depend on the doping material and the amount of the
dopant.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-05-418 |
| Date | 2009 May 1900 |
| Creators | Stephens, Matthew |
| Contributors | Petersen, Eric |
| Source Sets | Texas A and M University |
| Language | English |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | application/pdf |
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