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Hartdegen, Vera (2016): Energetic polymers and plasticizers based on organic azides, nitro groups and tetrazoles: synthesis and characterization. Dissertation, LMU München: Faculty of Chemistry and Pharmacy



The aim of this thesis was the development and investigation of new energetic polymers and plasticizers, on the basis of different polymer backbones or organic compounds with varying energetic or nitrogen-rich functional groups, along with the syntheses of suitable precursors for further (polymeric) processing. One of the main requirements of the newly developed compounds was their suitability as energetic binder or plasticizer, respectively, which includes high thermal and physical stabilities (to stabilize the energetic filler) and moderate to good energetic properties. In order to guarantee a good and save handling as well as a long storage time of the bound formulation, it is also mandatory that the developed compounds possess a high chemical stability, thus reactions with the energetic filler can be avoided. This thesis is divided into four sections. The first part is a continuation of my master thesis.1 It describes the synthesis and characterization of a glycidyl polymer containing nitramino groups. Known energetic polymers based on the glycidyl backbone possess energetic functional groups like azides (glycidyl azide polymer, GAP), or nitrate esters (poly(glycidyl nitrate), polyGLYN). As a new energetic compound based on the glycidyl backbone, a nitramine based polymer was developed, which was obtained in a four-step synthesis, using GAP as starting material. Analytical data as well as the results of the sensitivity testing and detonation parameter calculations have been accepted for publication in the Central European Journal of Energetic Materials. The second part attempted the syntheses and investigation of energetic polyurethanes, polyureas and related polymers, using hexamethylene diisocyanate, diisocyanato ethane and diisocyanato methane with several energetic and nitrogen-rich diols, diamines, dicarbamates and dihydrazides. It turned out that only the polyaddition reactions with diols towards polyurethanes were successful and resulted in satisfying analytical and energetic data. Parts of the results of the polyurethane investigations have been accepted for publication in the Journal of Applied Polymer Science. The third topic focuses on the investigation of polymers on the basis of mono- and difunctionalized tetrazolyl epoxides. For the syntheses towards the mono- and difunctionalized epoxy precursors several starting materials were prepared. Amongst others, two different constitutional isomers of divinyl and bisallyl derivatives of 1,2-bis(tetrazole-5-yl)ethane were successfully synthesized and characterized. The attempted syntheses following different reaction paths towards the desired epoxides only revealed traces of the desired compounds in the reaction medium or yielded monoepoxy compounds instead of the difunctional molecules. Results of analytical and physical data concerning the divinyl and bisallyl derivatives of 1,2-bis(tetrazole-5-yl)ethane were submitted for publication in Zeitschrift für Naturforschung B − A Journal for Chemical Science. Subject of the fourth part of this thesis is the synthesis of energetic plasticizers on the basis of 2,2-bis(azidomethyl)propane-1,3-diol, 2,2-dinitropropane-1,3-diol and 1,2-bis(hydroxyethyl tetrazole-5-yl)ethane. The syntheses were carried out in a one-step synthesis with three different acyl chlorides, varying in carbon chain length. The synthesized compounds were investigated regarding their high and low temperature behavior, as well as their plasticizing effects by analyzing certain properties of mixtures of them with two different energetic polymers. Parts of these results have been submitted for publication in Propellants, Explosives, Pyrotechnics.