No description available.

No description available.

Polybutadienes, polymerized via free radical mechanism to give an average molecular weight of 3000, were analyzed with carbon-13 NMR. The relative abundance of the three types of structural units (cis-1,4, trans-1,4, and vinylic-1,2 units) was quantitatively determined. The distribution of the three structural units was found to be completely random. Branching in the analyzed polymer was determined to be low (estimated to be less than 3 %). In hydroxyl-terminated-polybutadiene, two separate resonance signals from the hydroxyl-bearing end carbons were observed. Six isomeric dinitrotoluenes and four isomeric trinitrotoluenes were characterized with carbon-13 chemical shifts, which can be used in the qualitative and quantitative analysis of mixtures of these compounds. Multiple linear regression analysis was performed on the chemical shifts to obtain parameters which are useful in estimating the chemical shifts of carbon-13 nuclei of methyl- and nitro- substituted benzenes. Carbon-13 chemical shifts of other propellant ingredients (aliphatic nitrate esters, carboranes, plasticizers and stabilizers) are reported. / Master of Science

No description available.

No description available.

The experimental apparatus employed in this investigation permitted a fuel droplet and an oxidizer droplet to collide in a nitrogen atmosphere at temperatures from 50°C to 430°C. The resulting phenomena were photographed with a 16mm Fastax camera. Experimentation was completed in three series of tests. The first series consisted of impacting hydrazine droplets with white fuming nitric acid droplets at an impact velocity of 35 cm/sec and at temperatures from 200°C to 425°C. The second series utilized the same fuel and oxidizer at an impact velocity of 122 cm/sec and at temperatures ranging from 50°C to 430°C. The third series employed an alcohol-aniline mixture as the fuel droplets, and white fuming nitric acid as the oxidizer droplets. The impact velocity was 35 cm/sec and the nitrogen temperature ranged from 50°C to 415°C. Ignition was not obtained in the two series employing hydrazine as a fuel. The droplets, upon colliding, underwent a chemical reaction and were blown apart. With the series utilizing an alcohol-aniline mixture as the fuel, the droplets, after collision, formed one large drop which vaporized rapidly. The vapors ignited with flame at temperatures over 200°C. / Master of Science

Ph. D.

The analysis of nitrate-ester propellants and explosives has been performed extensively by gas chromatography for the past decade. As capillary GC technology has advanced, new opportunities for the improvement of existing methods have developed. This investigation probes several of these possibilities. The effect on quantitation of: the solvent, the analysis time, and the use of splitless injection were investigated. Precision was shown to be improved by: 1. using a non-volatile solvent (toluene) rather than CH₂Cl₂, 2. using the most time-efficient method that will allow adequate resolution of the components, 3. using splitless injection (0.80 min. splitless time). After these potential improvements of method were investigated, the mechanism employed in splitless injection was investigated. This mechanism is known as the SOLVENT EFFECT. The investigation showed that: 1. non-volatile components required less splitless time to achieve 100% sample transfer to the column; 2. using splitless injection improved precision over split injection; 3. injector liner design had no effect on precision; 4. column overload did not hurt precision, as long as all peaks remain baseline-resolved; 5. the initial column temperature must be below the boiling point of the solvent (how far below did not appear to be very significant); 6. quantitation is improved by using a solvent that is as non-volatile as possible; 7. varying the split ratio after the split vent has reopened (within the range of 20:1 to 500:1) has no effect on resolving peaks that occur extremely close to the solvent peak. / Master of Science

With an increase of interest in space flight and vacuum research, there has been a corresponding increase in the need for values of outgassing rates of many materials. In space flight the knowledge of the outgassing rates of components and materials used in construction of space vehicles allow the determination of pressures within sections of the vehicle, the contamination level of critical components, and the reliability of vehicle components. In the construction of an ultra high vacuum facility, the knowledge of the value of the outgassing rates of construction materials allows the chamber to be constructed of low outgassing materials, minimizing the amount of gas evolving from the chamber walls. With the initiation of a research program, the outgassing rates of the chamber, test objects, and instrumentation are needed to determine the level of vacuum obtainable during the investigation.<br /> With the increased need for outgassing rates, more emphasis has been placed on the measurement of outgassing rates. The literature reports several techniques for the measurement of outgassing rates. Of these techniques, the rate of rise method is simple and convenient to apply, and hence of much interest. Because it is simple and easily applied, the rate of rise technique has been used by many experimenters to measure the outgassing rates of various materials. However, some experimenters have rejected its use as they felt that the dynamic nature of the technique introduced large errors into the outgassing measurements. There is presently in the literature no technical evaluation of the rate of rise method as to the suitability or unsuitability for measuring outgassing rates. / Master of Science

In order to gain a fundamental understanding of actual solid propellant thermal stress problems, the geometry of the solid propellant baa been idealized as a short, circular cylinder with flat ends. It is felt that the consideration of actual curved ends would only unduly have complicated the analysis. The method of solution for the thermal stresses in the finite cylinder, that has been presented in this thesis, utilizes an arbitrarily selected set of cylinder end-conditions. Therefore, different end conditions than the ones employed here might have been considered just as easily. The fundamental difficulties encountered in the thermoelastic analysis of short cylinders are that firstly the problem is at least two-dimensional and secondly, it has mixed boundary conditions since displacements and/or stresses specified along at least four distinct boundaries. It is relatively simple to solve the governing differential equation by the method of separation of variables. The greatest difficulties are encountered in satisfying the various boundary conditions. As a matter of fact the method of solution for the thermal stresses that has been presented in this thesis is applicable only when the temperature distribution throughout the propellant and casing exhibits a particular variation in the axial direction, as shown by Eqs. (39) and (43). With such temperature fields, however the elastic analytic solutions that have been presented are significant since the simultaneous linear algebraic equations, for the arbitrary constants, are easily solved. It is true that, in principle, an infinite number of these arbitrary constants must be determined. From a practical point of view, however, the arbitrary constants can always be reduced to a finite number by truncating the obtained series solutions for the thermal displacements and stresses. / Master of Science