Study On Synthesis And Properties Of Geminal-dinitro Compounds

Geminal-dinitro compounds was an excellent energy-containing material with highenergy, stable features and good plastication effect. As important energy-containing materials,2,2-dinitropropanol and2,2-dinitro-1,3-propanediol were the most important intermediateproduct of gem-dinitro energetic compounds.2,2-dinitropropanol was prepared by silvernitrate oxide and2,2-dinitro-1,3-propanediol was prepared by potassium ferricyanide-sodiumpersulfate oxidation in this paper. The best synthesis scheme was determined by optimizingexperimental conditions and bis (2,2-dinitropropyl) formal was successfully synthesizedwhich was a typical geminal-dinitro energetic plasticizer.This thesis mainly focused andstudied on the following aspects:1. Confirming the best synthesis conditions of2-nitropropanol. The optimal reactionconditions which was confirmed by studying on materials ratio, reaction temperature andextracting agent of experiment was determined as follows: materials ratio was1.1:l:1.2;reaction temperature was0℃;optimal extracting agent was ethylacetate. The purity of productreached99.5%which was determined by gas chromatography and diopter and structure wascharaeterized by1H-NMR.2. Confirming the best synthesis conditions of2,2-dinitropropanol.On the best experimentconditions which has been determined in the first step, the second step nitrification oxidationwas synthesized by using silver nitrate oxidation. The effect on product yield and purity ofsilver nitrate dosage and oxidation reaction time were investigated by single factor method.The optimal reaction conditions: the most suitable dosage of silver nitrate was0.20mol;optimum reaction time was3h.The purity of product reached91.7%which was determined bygas chromatography and structures of product were identified by FT-IR and NMR.Micromelting point meter was also used to measure melting point.TG showed that initialdegradation temperature of DNPOH was about167℃and the char yield was nearly0whentemperture was285℃.3. Confirming the best conditions of synthesising2,2-dinitro-1,3-propanediol.2,2-dinitro-1,3-propanediol was synthesized using nitromethane, formaldehyde and sodium nitrite as rawmaterials and K3Fe(CN)6-Na2S2O8as oxidation system.The influence of materials ratio,Na2S2O8dosage, reaction temperature, reaction time were explored.The optimal reactionconditions: materials ratio was1.05:1:2.1; Na2S2O8dosage was0.30mol; reaction temperaturewas-5℃;reaction time was5h.The structures of product wereidentified by FT-IR and1HNMR.TG showed that initial degradation temperature of DNPOH was about163℃and thechar yield was nearly0when temperture was350℃. 4. Synthesis and application of bis (2,2-dinitropropyl) formal.Bis (2,2-dinitropropyl)formal (BDNPF) was synthesized from aldol condensation of s-Trioxane with DNPOH,concentrated sulfuric acid as catalysis, followed by purification.The structures of productwere identified by FT-IR and NMR.TG showed that initial degradation temperature ofDNPOH was about156℃a nd the char yield was nearly0when temperture was260℃.Viscos-ity tests showed that BDNPF had good performance in lower viscosity of GAP polymer from6.136Pa.s to1.121Pa.s at30℃a nd from1.053Pa.s to0.286Pa.s at60℃.