bluuebunny/crossref_metadata_2025_split huggingface dataset:
Zur Oxidationsstabilisierung von Cyclopentadienpolymeren. I. Polymerisation von Cyclopentadien und Chlorierung des Polymeren
Authors: Heublein Günter , Freitag Werner 
Published: January 2005

AbstractCyclopentadien wurde in Tetrachlorkohlenstoff mittels Aluminiumchlorid polymerisiert. Das erhaltene Polycyclopentadien (PCPD) wurde unter Variation des Lösungsmittels, der Temperatur, der Chlorkonzentration und unter Verwendung bestimmter Zusätze chloriert. Das chlorierte Polycyclopentadien (CPCPD) besitzt einen Chlorgehalt bis zu 63 Masse‐%. Die Produkte wurden hinsichtlich ihrer physikalisch‐chemischen Eigenschaften charakterisiert. CPCPD mit Chlorgehalten über 45 Masse‐% bleibt über Monate an der Luft farbstabil und löslich. Die Oxidationsrate wird gegenüber PCPD stark zurückgedrängt und ist über die Gewichtszunahme nicht mehr meßbar. Die thermische Stabilität und die Anfälligkeit gegen Oxidations‐ und Eliminierungsprozesse verbessern sich mit steigendem Chlorgehalt der Produkte.
Über die Natur der Übergangsmetall‐Kohlenstoff‐σ‐Bindung. II. Massenspektrometrische Untersuchungen von Mono‐organyl‐Übergangsmetallkomplexen des Phthalocyanins und Salens
Authors: Müller E.‐Ch. , Kraft R. , Etzold G. , Drevs H. , Taube R. 
Published: January 2005

The Nature of the Transition Metal to Carbon σ‐bond. II. Mass Spectrometric Investigations of Mono‐organyl‐Transition Metall Complexes of Phthalocyanine and SalenIn the mass spectra of monomethyl and monophenyl complexes of Fe(III) and Co(III) phthalocyanines (RMPc) there are observed peaks at higher mass numbers than that of the molecular ion which are described to products containing more than one organyl group.It is concluded from the mass spectra and the ionization efficiency curves of the ions R2MPc+, RMPc+ and MPc+ that, due to the high temperature in the inlet system of the mass spectrometer, in the solid state a loss of the organyl residue R and an attack of the radicals at the phthalocyanine ring takes place.The mass spectra of methyl‐ and phenyl‐cobalt(III)‐salen do not contain any peaks at higher mass numbers than the molecular ion. The problems of mass spectrometric determination of the strength of the transition metal to carbon σ‐bond are discussed.
Stobbe Condensation of Aromatic Aldehydes with Diethyl Diglycollate
Authors: Salem M. R. , Enayat E. I. , Kandil A. A. 
Published: January 2005

AbstractPiperonal, p‐tolualdehyde, and p‐chlorobenzaldehyde condense with diethyl diglycollate in the presence of sodium hydride to give predominantly the corresponding (Z)‐half‐esters 1. together with smaller yields of the diarylidene diacids 2 and 3. The structure and configuration of the products was established by chemical and spectroscopic evidence.
Reaktionen von 2,3‐Dichlormaleinimiden mit methylenaktiven Verbindungen
Authors: Augustin M. , Fischer G. , Schneider B. , Köhler M. 
Published: January 2005

Reactions of 2,3‐Dichloromaleimides with Methyleneactive Compounds2,3‐Dichloromaleimides 1 react with activated methylene compounds mainly under monosubstitution to give 2–6. Replacement of the second chloroatom gives 2,3‐disubstituted maleimides 9–15 and stable ylides 16–27 with pyridine and triphenylphosphine, respectively. A general synthesis for such maleimid‐ylides was found in a one‐batch reaction from 2,3‐dichloromaleimides 1 with methyleneactive compounds and pyridine or triphenylphosphine.
Zur Chemie des Triacetonamins. III. Verlauf und Produkte der Umsetzung von Isocyanaten mit 2,2,6,6‐Tetramethylpiperidin‐4‐onoxim
Authors: Werchan Hans Georg , Russew Russi Iwanow , Held Paul , Schubert Hermann 
Published: January 2005

Triacetoneamine Chemistry. III. Course of and Products from the Interaction of Isocyanates with 2,2,6,6‐Tetramethylpiperidine‐4‐one OximeReaction between 2,2,6,6‐tetramethyl‐piperidine‐4‐one oxime 2 and isocyanates RNCO in equimolar amounts yields the corresponding O‐carbamoyl derivatives 3. These compounds are converted to the N, O‐dicarbamoyl derivatives 4 by treating 3 with another mole of the same or a different isocyanate.Under mild conditions the N‐carbamoyl moiety of the compounds 4 splits off by thermolysis or hydrolysis resulting in reproduction of the more stable 3. The regiospecifity of the carbamoylation reaction 1 → 3 and of the reverse reaction 4 → 3 is considered as a consequence of steric hindrance in position 1 of the heterocyclus.
13C‐kernmagnetische Resonanzspektren der Phenylfulgide
Authors: Ilge H.‐D. , Paetzold R. , Radeglia R. 
Published: January 2005

Carbon‐13 Nuclear Magnetic Resonance Spectra of PhenylfulgidesThe carbon‐13 chemical shifts are determined in a series of phenylfulgides in order to investigate steric and electronic influences of substituents. By means of the shift differences between suitably substituted compounds results can be obtained as to the relative variation of the rotation angles of the phenyl rings as well as to te angle alterations between the exocyclic double bonds and the anhydride ring. Introducing 4‐CH3O‐ and 4‐NO2‐groups at the phenyl rings the substituent induced alterations of the carbon‐13 chemical shifts and the π‐polarization effects related with it are discussed.
13C‐NMR‐Spektren von 2‐Bromcholest‐5‐en‐3‐onen
Authors: Römer J. , Scheller D. , Grossmann G. 
Published: January 2005

13C‐N.M.R. Spectroscopic Investigation of 2‐Bromo‐cholest‐5‐en‐3‐onesThe 13C‐n.m.r. spectra of the 2‐epimeric 2‐bromocholest‐5‐en‐3‐ones have been measured and the substituent effects are determined. The substituent effects of 2‐Br and Δ5 double bond follow the rules known from literature.
Reaktionen des 2,6‐Di‐tert.‐butyl‐4‐(N‐tert.‐butylnitrono)‐phenoxyradikals
Authors: Schulz Manfred , Bach Barbara , Reinhardt Michael 
Published: January 2005

Reactions of the 2,6‐Di‐tert.‐butyl‐4‐(N‐tert.‐butylnitrono)‐phenoxyl RadicalThe title compound, a phenoxyl radical containing a nitrono group, reacts with alcohols and tert.‐butylhydroperoxide yielding phenol and products of secondary radical solvent reactions. The reactions with lead tetraacetate, tert.‐butoxy and 2‐cyanoisopropyl radicals give high yields of cyclohexadienone adducts (6, 7 and 10) containing unchanged nitrono function. The reaction with dibenzoylperoxide, however, leads to the modification of the nitrono group yielding the N‐benzoyloxycarboxamide (8). In the acidic decomposition of the tert.‐butoxy radical adduct we suggest a nitrenium ion (16) as an intermediate.
Reaktionen von 2‐Cyan‐3‐methoxy‐maleinimid mit methylenaktiven Verbindungen und Enaminen
Authors: Augustin M. , Frank J. , Köhler M. 
Published: January 2005

Reactions of 2‐Cyano‐3‐methoxy‐maleinimide with Methylene Active Compounds and EnaminesThe vinylogous ester 1 gives with methylenactive compounds 2 carbamoylmaleinimides 3, which cyclize to pyridonimides 4. Reactions of 1 with enamines form cyanomaleinimides 6‐8 and aminopyridines 11.
Synthesis of new nitrile imines with Pyridazin‐3(2H)‐one moiety and their addition to some dipoles. I
Authors: Shams Nabil A. 
Published: January 2005

AbstractThe present work deals with the synthesis of 6‐aryl‐2‐ethoxycarbonyl pyridazin‐3(2H)‐ones (2) as useful synthetic intermediates because they allow formation of a new hydrazides (3), hydrazidoyl chlorides (4) and the highly reactive nitrile imine species (5). Dimerization and reaction of the latter species with benzonitrile, benzaldehyde and their p‐methoxy and p‐nitro derivatives provides a convenient method for the synthesis of substituted 1, 2, 4, 5‐tetrazines (6), 1, 2, 4‐triazoles (7) and 1, 3, 4‐oxadiazoles (8), respectively, with pyridazin‐3(2H)‐one moiety.
Phosphororganische Antioxidantien. III. Kinetik und Mechanismus der Cumylhydroperoxidzersetzung durch cyclische Phosphite
Authors: Rüger C. , König T. , Schwetlick K. 
Published: January 2005

Organophosphorus Antioxidants. III. Kinetics and Mechanism of the Decomposition of Cumyl Hydroperoxide by Cyclic PhosphitesThe reaction mechanism of cyclic esters of phosphorous acids I to VIII with cumyl hydroperoxide has been studied kinetically by means of 31P n.m.r. spectroscopy, high performance liquid chromatography and iodometric titration.The five‐membered cyclic phosphites (I and II) react with cumyl hydroperoxide to give the corresponding phosphates (AI and AII) and cumyl alcohol. With more hydroperoxide or water they form the open chain phosphate esters (BI and BII) which decompose cumyl hydroperoxide catalytically giving phenol and acetone. Higher membered cyclic phosphites (III to VIII) react with cumyl hydroperoxide to give the corresponding phosphates and alcohol only. The mode of reaction depends on the hydrolysis behaviour of the cyclic phosphates (AI to A VIII). Only fivemembered cyclic phosphites which give easily hydrolyzable phosphates are able to decompose cumyl hydroperoxide catalytically. The nature of the exocyclic group in the phosphites has no influence on this behaviour.The kinetic parameters of the separate reaction steps are given.The ionic mechanism of hydroperoxide decomposition is accompanied by a homolytic one.
Pyryliumverbindungen. XXII. 1H‐NMR‐ und UV‐spektroskopische Untersuchungen zur Isomerisierung von Pseudobasen unsymmetrisch substituierter 2, 4, 6‐Triarylpyryliumsalze
Authors: Fischer Gerhard W. , Mügge Clemens , Fink Siegfried 
Published: January 2005

Pyrylium Compounds. XXII. 1H‐N.M.R. and U.V. Spectroscopic Investigations on the Isomerization of Pseudobases of Unsymmetrically Substituted 2, 4, 6‐Triarylpyrylium SaltsThe kinetics and mechanism of the isomerization of the title compounds, the pentene 1,5‐diones 2 and 3, were studied by 1H‐n.m.r. and u.v. spectroscopy. The equilibrium constants measured vary little near 1, indicating the small influence of substituents on the equilibrium position. The mutual rearrangement 2⇄3 proved to be a base‐catalized reaction which is characterized by strictly linear Hammett correlation between 1g k and Σσp. The results obtained suggest resonance‐stabilized anions of type4 as intermediates. ‐ Pseudobases of 3‐alkyl‐2, 4, 6‐triarylsubstituted pyrylium salts do not undergo a reversible isomerization.
Pyryliumverbindungen. XXIII. 2‐Dialkylamino‐2H‐pyrane aus tetra‐ und pentasubstituierten Pyryliumsalzen
Authors: Fishcer Gerhard W. , Zimmermann Thomas , Weissenfels Manfred 
Published: January 2005

Pyrylium Compounds. XXIII. 2‐Dialkylamino‐2H‐pyrans from Tetra‐ and Pentasubstituted Pyrylium Salts.Tetra‐ and pentasubstituted pyrylium salts of type 6 react with secondary alkyl amines to give stable crystalline 2‐dialkylamino‐2h‐pyrans 7. In the case of tetrasubstituted pyrylium salts 6, R′ = Me, R″ = H the reaction occurs regioselectively leading to 2H‐pyrans with Me at C‐3 of the heterocyclic ring. The structure of the reaction products was established by n.m.r., i.r., u.v. and mass spectroscopic methods. Electrophilic agents like protons, carboxylic acid chlorides or methyl iodide regenerate the original pyrylium cations from 7. In refluxing methanol 7a is converted into the 2‐methoxy‐2H‐pyran derivative 8, whereas in aqueous acetone the pseudobase 9 and with ammonia the pyridine 10 are formed. Reaction of 7a with nitromethane or ethyl cyanoacetate provides the benzene derivatives 11 and 12, respectively.
β‐Fur‐2‐yl‐α‐halogenacrylonitrile. IV. Reaktionen von β‐Fur‐2‐yl‐α‐halogenacrylonitrilen mit Alkoholen und Phenolen
Authors: Jähnisch K. , Callejas D. R. , Catasus N. 
Published: January 2005

β‐Fur‐2‐yl‐α‐halogenacrylonitriles. IV. Reactions of β‐Fur‐2‐yl‐α‐halogenacrylonitriles with Alcohols and Phenolsβ‐Fur‐2‐yl‐α‐halogenacrylonitriles 1a–c react with alcohols and phenols to yield β‐fur‐2‐yl‐β‐alkoxyacrylonitriles and β‐fur‐2‐yl‐β‐aroxyacrylonitriles 2a–k respectively. With ethylene glycol α‐[2‐(fur‐2‐yl)‐1, 3‐dioxolan‐2‐yl]acetonitriles 3a, b are formed.
Zur Struktur des „Trichlor‐diphenoxyphosphorans”︁
Authors: Gloede J. , Gross H. , Waschke R. 
Published: January 2005

The Structure of “;Trichloro‐diphenoxyphosphorane”The structure of ‘Trichloro‐diphenoxyphosphorane’ synthesized by well‐known and new methods is not a pentacoordinated phosphorus compound, but has the structure of tetraphen‐oxyphosphonium hexachlorophosphate 4.
Zur Rhodium‐katalysierten Carbonylierung aromatischer Nitroverbindungen zu Isocyanaten. III. Zur Sauerstoffübertragung bei der Carbonylierung von Nitromesitylen in Gegenwart von Rhodium(I)carbonylchlorid und Molybdänoxychlorid
Authors: Unverferth Klaus , Tietz Helmuth , Schwetlick Klaus 
Published: January 2005

Rhodium Catalyzed Carbonylation of Aromatic Nitro Compounds to Form Arylisocyanates. III. On Oxygen Transfer in the Carbonylation of Nitromesitylene in the Presence of Rhodium(I)Carbonyl Chloride and Molybdenum OxytrichlorideRh2Cl2(CO4) and MoOCl3 or MoOCl4 catalyze the carbonylation of nitromesitylene to form mesityl isocyanate at 1000C and normal pressure. Experiments with Mo18OCl3 show that the deoxygenation of the nitro group proceeds directly by the CO ligand. The 18O‐atom of the cocatalyst is not involved in the oxygen transfer process. Experimental evidence is given for the formation of an oxomolybdenum complex in situ containing the deoxygenated nitromesitylene as a structure unit.
Lone pairs and molecular structure: The Conformation of the o,o′‐Azabiphenyls
Authors: Hofmann H.‐J. , Birner P. 
Published: January 2005

AbstractThe conformational structure of the o,o′‐azabiphenyls was examined using the NDDO method. The planarity or nonplanarity of the various compounds is the result of a compromise between the stabilizing conjugation effect and the destabilizing interactions of the nitrogen lone pairs and the steric hindrance of the ortho hydrogen atoms, respectively. There are no destabilizing interactions between the ortho hydrogens and nitrogen lone pairs. A detailed analysis of the results provides more insight into the problems of the treatment of lone pairs within NDO methods.
Cyclisierungsreaktionen β,γ‐ungesättigter Kohlensäurederivate. X. Reaktionen von N‐Cinnamylcarbamidsäureestern mit Sulfenylchloriden‐Synthese von 3, 5‐disubstituierten Oxazolidin‐2‐onen
Authors: Mühlstädt M. , Olk B. , Widera R. 
Published: January 2005

Cyclization Reactions of β,γ‐Unsaturated Derivatives of Carbonic Acid. X. Reaction of N‐Cinnamyl Carbamic Acid Esters with Sulfenyl Chlorides—Synthesis of 3,5‐Disubstituted Oxazolidine‐2‐onesN‐Cinnamyl urethanes 1 have been cyclized to 3,5‐disubstituted oxazolidine‐2‐ones 3 by aromatic sulfenyl chlorides in methylene chloride. The tetrahydro‐2H‐1,3‐oxazine‐2‐ones 6 were obtained by reaction of 5‐bromotetrahydro‐2H‐1,3‐oxazine‐2‐ones 8 with thiophenols.
Determination of the difunctional primary products in the Oxidates of Medium n‐Paraffins
Authors: Chhaly Leang , Peitzsch Rüdiger , Pritzkow Wilhelm , Voerckel Volkmar , Zewegsuren Nansadyn 
Published: January 2005

AbstractThe proportion of difunctional and monofunctional products with the original carbon skeleton was determined in the oxidates of n‐decane, n‐tridecane, n‐pentadecane, and n‐octadecane to about 0.32. This proportion does not significantly depend on the conversion of the starting paraffin. As well as mono‐ and difunctional products with the original carbon skeleton already at very low conversions of n‐tridecane, about 45% of lower oxygen‐containing compounds, for example aldehydes, alkan‐2‐ones, carboxylic acids and γ‐lactones, are also obtained. Obviously, a part of the difunctional primary products reacts very fast with scission of the carbon chain, forming lower oxygen‐containing compounds.
Activated nitriles in heterocyclic synthesis: A Novel Synthesis of Pyrimidine Derivatives
Authors: Ibrahim Nadia Sobhy , Shams Hoda Zaki , El‐Aal Fatma Abd El‐Maksoud Abd , Elnagdi Mohamed Hilmy 
Published: January 2005

AbstractThe reaction of 3‐amino‐2,4‐diethoxycarbonylcrotononitrile with cinnamonitrile derivatives afforded the pyrimidines 5a‐‐d and not the pyridines 4 as expected from literature. Similarly pyrimidines 5e‐‐h were produced when 3‐amino‐2,4‐dicyanocrotononitrile was treated with the same reagent. The structure was established based on MS and high resolution 1H‐n.m.r. spectroscopy.
Synthese von (Z/E)‐1‐Aryl‐4‐arylmethylen‐pyrrolidin‐2,3,5‐trionen und Reaktionen mit Heteronucleophilen
Authors: Augustin M. , Jeschke P. 
Published: January 2005

Synthesis of (Z/E)‐1‐Aryl‐4‐arylmethylene‐pyrrolidine‐2,3,5‐triones and Reactions with HeteronucleophilesThe condensation reaction of 2‐hydroxy‐maleimides 1 prepared in situ from 2‐ethoxycarbonyl‐3‐hydroxy‐maleimide 2 or the amide ester 3 with aldehydes afforded in a one‐pot procedure the (Z/E)‐1‐aryl‐4‐arylmethylene‐pyrrolidine‐2,3,5‐triones 5a–k in good yields.Acid catalyzed treatment of the α,β‐unsaturated carbonyl compounds (Z/E)‐5a, c, g with bifunctional nucleophiles such as thiourea and phenylthiourea gave the derivatives of 1,3‐thiazine‐2‐ones 8a–d respectively, while (Z/E)‐5f and urea produced the pyrimidine‐2‐ones 9. Under the insemicarbacide led to the formation of the (Z/E)‐isomers 10a–f.Triethyl phosphite added in a Michael fashion to yield the novel 3‐aryl‐2,2,2‐triethoxy‐Δ4‐oxaphospholene‐4,5‐dicarboxylic imides 11a–c.
Elektrochemie organischer Kationen. V. Synthese von 3, 10‐Diaza‐tricyclo[5.3.1.1.2,6]dodeca‐4,8‐dien‐Derivaten durch zweistufige Elektroreduktion von Pyridiniumionen
Authors: Pragst F. , Köppel H. , Walkhoff E. , Boche E. 
Published: January 2005

Electrochemistry of Organic Cations. V. Synthesis of 3, 10‐Diaza‐tricyclo[5.3.1.12,6]dodeca‐4,8‐diene Derivatives by a Two‐Step Electrochemical Reduction of Pyridinium IonsA series of 1‐substituted 2,4,6‐trimethylpyridinium ions 1a–1k is cathodically dimerized in alkaline medium. The bis‐[1,4‐dihydropyridinyl‐(4)]‐derivatives 2 obtained or their isomers 4 are submitted to a further cathodic reduction in aqueous acetic acid at mercury or lead electrodes to form 3,10‐diaza‐tricyclo[5.3.1.12,6]dodeca‐4,8‐dienes 6 by an intramolecular coupling reaction between the 2‐ and 2′‐carbon atoms of the dihydropyridine rings. Depending on R1 the yields of 6 are 65–80% (R1 = alkyl or substituted alkyl) or 3,5–5% (R1 = aryl).
Reactions with β‐ketodianilides. I. New synthesis of Pyrido[3,4‐c]pyridine Derivatives
Authors: El‐Reedy A. M. , Ibrahim M. K. A. , Hussain S. M. , Moharram H. H. 
Published: January 2005

AbstractAcetonedicarboxylic acid dianiline reacted with malononitrile, ethyl cyanoacetate or benzoylacetonitrile to give (6‐amino‐5‐cyano‐1,2‐dihydro‐2‐oxo‐1‐phenylpyrid‐4‐yl)‐acetanilide (3), (3‐cyano‐2,6‐dioxo‐1‐phenyl‐1,2,5,6‐tetrahydropyrid‐4‐yl)acetanilide (8) or (3‐cyano‐1,6‐dihydro‐1,2‐diphenyl‐6‐oxopyrid‐4‐yl)acetanilide (9). Compounds 3 and 8 could be cyclised into 8‐amino‐1,6‐diphenyl‐1,2,4,5,6,7‐hexahydro‐7‐iminopyrido[3,4‐c]pyridine‐2,5‐dione (4) and 7‐amino‐1,2,3,5,6,8‐hexahydro‐1,6‐diphenylpyrido[3,4‐c]pyridine‐2,5,8‐trione (10) respectively by heating their solutions in dimethylformamide in the presence of triethylamine. Each of 3 and 4 coupled with arenediazonium chlorides to give the corresponding arylhydrazone derivatives (5a–d) and (6a–c), respectively. Condensation of 4 with p‐nitrosodimethylaniline yielded 8‐amino‐4‐ (p‐dimethylaminophenylimino)‐1,6‐diphenyl‐1,2,4,5,6,7‐hexahydro‐7‐iminopyrido[3,4‐c]pyridine2,5‐dione (7).
Reaktionen von β‐Chlorvinylaldehyden. V [1]. Zur Bildung von 2,2′‐Thiopyrylotrimethinfarbsalzen aus 2‐(α‐Formylalkyliden)‐2H‐thiopyranen
Authors: Weissenfels M. , Pulst M. , Greif D. , Hollborn B. 
Published: January 2005

Reactions of β‐Chlorovinylaldehydes. V. The Formation of 2,2′‐Thiopyrylocyanine Dyes from 2‐(α‐Formylalkylidene)‐2H‐thipyranesSubstituted β‐chlorocrotonaldehydes react with Na2S · 9H2O to form 2‐(α‐formyl‐alkylidene)‐2H‐thiopyranes 1. The corresponding thiopyrylium salts 2 which are easily available from 1 and strong acids exist in the enolic form (2‐β‐hydroxyvinyl‐thiopyrylium salts). They are converted at room temperature in methanol solution to dark green compounds, which are identified as 2,2′‐thiopyrylotrimethincyanine dyes 3. The mechanism of formation of compounds 3 is discussed.
The Relation between Packing Effects and Solid State Fluorescence of Dyes
Authors: Langhals H. , Demmig St. , Potrawa Th. 
Published: January 2005

AbstractThe solid state fluorescence of diketopyrrolopyrrole dyes and perylene‐3,4:9,10‐ tetracarboxylic bisimides with alkyl substituents are investigated and compared with noncovalent interactions. The latter are estimated by crystal structure analysis, heats and entropies of fusion and solubilities in organic solvents. Applications of the dyes are discussed.
Struktur — Retentionsbeziehungen von stereoisomeren methylsubstituierten Isochromanen in der Gaschromatographie
Authors: Meusinger R. , Engewald W. 
Published: January 2005

Structure ‐ Chromatographic Retention Relationships of Stereoisomeric Methyl‐substituted IsochromanesRetention times of 13 mono‐, di‐ and trimethylsubstituted isochromanes are determined on both polar (PEG) and nonpolar (OV‐1) stationary phases and KOVATS retention indices (I) are calculated. The significant retention index differences (ΔI) between stereoisomers (up to 30 units) are discussed with respect to the configurational and conformational arrangement of the substituents. Retention indices determined by gas‐solid‐chromatograhpy (GSC) on graphitized thermal carbon black (GTCB) complete the research.
Determination of the crater radius as a function of time of a shaped charge jet that penetrates water
Authors: Held Manfred , Huang N. S. , Jiang D. , Chang C. C. 
Published: December 2004

AbstractThe new technique of measuring radial expansion of a crater as a function of time on a shaped charge jet that penetrates water is explained in this paper. Radial expansion of the crater in the frame of experimentation can, in this case, be easily described with a modified Bernoulli equation under the condition that target strength is weak, the initial radial crater velocity is equal to the axial crater velocity and that the pressure p diminishes from the initial impact pressure p0, with the ratio of the area a to the initial area a0 of the impacting jet.
Combustion Characteristics of High Burn Rate Azide Polymer Propellant
Authors: Nagayama Kiyokazu , Oyumi Yoshio 
Published: December 2004

AbstractThe combustion characteristics of high burn rate azide polymer composite propellant were examined by using a chimney type strand burner, a Ø 80 mm × 140 mm small rocket motor and a L/D = 16 of Ø 70 mm heavy‐wall rocket motor. The propellant, BAMO/NMMO copolymer was used as a fuel binder and AP as an oxidizer, burned approximately 29 mm/s at a pressure range of 7 MPa to 20 MPa with a plateau‐mesa burning behavior. However, the pressure exponent rapidly increased at above the pressure of 20 MPa and was 0.52 between 20 MPa and 25 MPa. The low pressure exponent and high burn rate of the azide polymer propellant are suitable to the short burn time at the maximum expected operating pressure range of 15 MPa to 20 MPa. The high L/D heavywall rocket motor with volumeric mass fraction of 83% showed stable combustion without any pressure oscillation and severe erosive burning. The average burn rate in the high L/D motor was 10% larger than that estimated from the strand data. The theoretically calculated pressure‐vs‐time and thrust‐vs‐time curves were well consistent with the measured data. α = 20 and β = 180 for the Lenoir‐Robillard equation were used to estimate the burn rate.