Granül ve Hidrofobik Film Yapılı Piroteknik/Termit Malzeme Sentezi ve Karakterizasyonu

Abstract

The aim of this thesis is to develop and characterization of granular and film pyrotechnics materials. Pyrotechnic materials are flammable which can ignite faster than other energetic material such as explosive and propellant and therefore they are highly sensitive to external effects (friction, impact etc). In this study, Aluminium metal and Boron semi-metal were used as fuel and different metal oxides (Copper (II) Oxide, Iron (III) Oxide and Molybdenum Oxide) were used as oxidizer in all pyrotechnic mixing. Polyvinylidene Fluoride (PVDF) was used that has good thermal and chemical stability and also high hydrophocity level as binder. All film and granular samples were prepared by mechanical mixing. Granular structures were mixed in hexane and film structures were mixed in DMF medium by using mechanical mixing method.In additon, film pyrotechnics also were prepared by ısing Mayer rod. The thermal behaviour of film and granular pyrotechnics were characterized by DSC/TGA Instrument and the combustion characteristics of samples were characterized by using Bomb Calorimetry. The products of gas and solid that occur after combustion were determined by XRD and TG-MS. The surface area of raw materials (metal,semi-metal,metal oxides) were measured by B.E.T method. Hydrophobic properties of film pyrotechnics were measured by Static Contact Angle Instrument. Theoretical calorific values of the samples were calculated by ICT-Code Programme. The result showed that the film pyrotechnic materials ignited 100-250 ºC earlier than the granular pyrotechnics due to PVDF's reactive structure. It was determined the solid burned product of granular pyrotechnics depending on their equvailence ratio and it was observed that as the equivalence ratio come close to stoichiometry, thermite reactions are more efficient and accordingly the solid burned product value increases between 1.65 and 4.4 times. The calorific value of all pyrotechnic mixtures were measured from 438 to 1008 cal/g depending on various oxidizer and fuel type, different equivalence ratio (from 1.5 to 12.5) and binder effect. It was seen that equivalence ratio is more affected on calorific value of pyrotechnics. Static contact angle test was performed for PVDF binder and this angle was measured as 101.67 º. By this means, it was shown that the film pyrotechnics are hydrophobic.