Enerjik Bağlayıcılar Olarak Poli[3,3-Bis(Azidometil)Oksetan] (PBAMO) Polimerlerinin Tasarımı, Sentezi ve Karakterizasyonu
Özet
The main purpose of the thesis is to design the molecular structure of the energetic Poly[3,3-bis(3-azidomethyl) oxetane] (BAMO) polymer, synthesize it and carry out characterization studies. Although hydroxy-terminated polybutadiene (HTPB), which is mostly used in solid fuel formulations today, offers reliable mechanical and thermal properties, interest in energetic polymers has increased day by day because it does not contain energetic groups in its structure and does not contribute to the formulation in this sense. With this understanding, replacing this inert polymer used as a binder in solid fuel formulations with an energetic polymer will also allow the design of insensitive ammunition due to lower oxidant loading. For this reason, the use of energetic polymers in formulations is very important as it increases the performance of fuel systems and provides safe opportunities. In studies aimed at obtaining the BAMO polymer, synthesis studies of Poly[3,3-bis(3-chloromethyl) oxetane] (PBCMO) polymer were first carried out as the starting polymer. Then, the -Cl groups in the structure of the starting polymer were subjected to a replacement reaction with potassium carboxylate groups. In the last step, azidation of the polymer was achieved using sodium azide in dimethyl sulfoxide environment. The molecular structures of the obtained copolymers (PBAMO-Carboxylate) were elucidated using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Proton Nuclear Magnetic Resonance (1H-NMR) spectroscopy methods. Additionally, the molar masses of the copolymer were calculated using Gel Permeation Chromatography.
Differential Scanning Calorimetry and Thermal Gravimetric Analysis methods were used to examine the thermal properties of the synthesized copolymers. Here, analyzes were carried out to determine the glass transition temperatures of the materials and the decomposition temperatures to determine the thermal stability of the structures. In addition, Bomb Calorimetry experiments were carried out to determine the combustion energies of energetic copolymers.
It has been observed that the thermal properties of BAMO polymer are improved by adding carboxylate groups to its structure. In this context, considering the improved thermal properties of the synthesized copolymers, there is potential for their use as binders in solid fuel formulations.