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  • 1
    ISSN: 1042-7147
    Keywords: Ferroelectric polymers ; Nonvolatile RAM's ; Optical data storage ; New polycarbonates with high heat resistance ; Structure-property relationships for polycarbonates ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Polymers possess great significance in data storage technology. Taking as an example electrical and optical data storage, the state of development, properties required and opportunities for application of selected polymers are discussed, namely: (i) ferroelectric polymers with low switching voltages and extremely short switching times for electric data storage; and (ii) transparent polymers with low birefringence and high thermal stability for optical data storage.In the area of electrical data storage devices/memories, ferroelectric polymers have not been able to establish themselves up to now due to their long switching time and limited thermal stability. However, recent investigations show that suitable copolymers based on PVDF/TrFE copolymers in ultra-thin layers can achieve switching times of ≤100 ns. Nevertheless, the limited thermal stability of PVDF/TrFE copolymers prevent them from being integrated into the usual manufacturing process for Si-based data storage devices (D-RAM resp. S-RAM) and thereby frustrates the desired objective of producing nonvolatile random access memories (NV-RAMs).In the area of optical data storage technology, polycarbonate (PC) has established itself due to its favorable combination of properties. Thus, audio compact disks (CDs) are manufactured exclusively of PC, while high-flow PC types of high optical purity are clearly the preferred substrate material for optical data storage disks. The increasingly stringent requirements to be met in terms of lower birefringence and better thermal stability mean that the development of suitable modified or substituted polycarbonates is required. The development work being carried out worldwide in this area is reviewed here, and new suitable substituted polycarbonates with lower birefringence and significantly increased thermal stability up to glass temperatures of 238°C are presented.In addition, we deduce structure - property relationships for the above-mentioned structurally modified polycarbonates, specifically considering rotation potentials along the polymer backbone.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: We present a new method for studying the influence of flame retardants as a function of time and temperature by measuring the X-ray absorption spectra of the corresponding additive. Here, red phosphorus in polyamide 6,6 was investigated at the phosphorus K-edge using synchrotron radiation. The thermo-oxidative degradation of the polymer was simulated by heating the sample up to 300°C. XANESXANES, EXAFS: X-ray absorption spectroscopy investigating the near edge structure or the fine structure of the extended region, respectively. spectra were monitored during the degradation process at different temperatures and at a constant reaction temperature as a function of time. The degradation reaction was analyzed by comparing the XANES spectra of red phosphorus and orthophosphoric acid, and the reaction was identified as an oxidation of red phosphorus to H3PO4. The results so obtained are confirmed by the EXAFS spectra of the additive in the polymer sample recorded before and after the thermo-oxidative degradation process, and by the EXAFS spectra of suitable reference compounds.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 355 (1967), S. 182-191 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1,2-Ethanedithiol and thioglycol react with arsenic(III) oxide forming the heterocyclic thioesters (C2H4S2)3 and (C2H4OS)3As2, which on interacting with AsIII halides comproportionate to ester halides, C2H4S2AsX and C2H4OSAsX. Because of the polar nature of the As-X bond, other ligands can easily substitute for X. Thus, various derivatives of 1,3,2-dithioarsolane and 1,3,2-thioxarsolane are obtainable.
    Notes: 1,2-Äthandithiol und Thioglykol bilden mit Arsen(III)-oxid die heterocyclischen Verbindungen (C2H4S2)3As2 und (C2H4OS)3As2. Diese Thioester lassen sich mit Arsentrihalogeniden zu den Esterhalogeniden C2H4S2AsX und C2H4OSAsX komproportionieren. Infolge des polaren Charakters der As-X-Bindung kann X leicht durch andere Liganden substituiert werden. Auf diese Weise gelangt man zu vielfältigen Derivaten des 1,3,2-Dithioarsolans und des 1,3,2-Thioxarsolans.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 355 (1967), S. 192-199 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Solvolysis of 2-chloro-1,3,2-dithioarsolane and 2-chloro-1,3,2-thioxarsolane with amines yields amides of the thioarsolanes, e. g. the methyl and dimethyl amides or an ethyleneimide. These amides, especially the dimethyl amides, are highly reactive compounds, interacting not only with H2O, H2S and CH3I, but also with acetic anhydride and diacetyl sulphide under substitution of the R2N group at the As. Further, CO2, CS2 and COS are added the amides giving carbamates and thiocarbamates of the thioarsolanes.
    Notes: Solvolyse von 2-Chlor-1,3,2-dithioarsolan und 2-Chlor-1,3,2-thioarsolan mit verschiedenen Aminen führt zu den Amiden der Thioarsolane. Neben den Methylamiden wurden Dimethylamide und ein Äthylenimid erhalten. Die Substanzen, besonders die Dimethylamide sind sehr reaktionsfähige Verbindungen, die sich mit Wasser, Schwefelwasserstoff und Methyljodid umsetzen. Auch mit Acetanhydrid und Diacetylsulfid tritt Substitution der am As gefundenen R2N-Gruppe ein. CO2, CS2 und COS werden von den Verbindungen addiert unter Bildung von Carbamaten und Thiocarbamaten der Thioarsolane.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 375 (1970), S. 55-60 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Elimination of HCl from 1,3-propanoldichloroarsine, HOC3H6AsCl2, yields 2-chloro-1,2-oxarsolane. Hydrolysis in the presence of triethylamine gives bis-1,2-oxarsolanyloxide. Bis-1,2-thioarsolanyl-sulphide is obtained from 1,3-chloropropyl-arsenicsulphide, (ClC3H6AsS)3, by interaction with thiourea and decomposition of the intermediate thiuronium salt. Reaction with AsCl3 yields the 2-chloro-1,2-thioarsolane which may be hydrolized to bis-1,2-thioarsolanyl-oxide.
    Notes: Durch HCl-Abspaltung wird aus 1,3-Propanol-dichlorarsin, HOC3H6 · AsCl2, das 2-Chlor-1,2-oxarsolan dargestellt. Hydrolyse in Gegenwart von Triäthylamin führt zu Bis-1,2-oxarsolanyl-oxid. Bis-1,2-thioarsolanyl-sulfid erhält man aus 1,3-Chlorpropylarsensulfid, (ClC3H6AsS)3, durch Umsetzen mit Thioharnstoff und Zersetzen des entstandenen Thiuroniumsalzes. Reaktion mit Arsentrichlorid liefert das 2-Chlor-1,2-thioarsolan, das zum Bis-1,2-thioarsolanyloxid hydrolysiert werden kann.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 370 (1969), S. 227-234 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclic carbonic acid esters, such as ethylene-, propylene-and trimethylene-carbonate are transesterified, under CO2 elimination, into dioxarsolanes and dioxarse-nanes by means of arsenic(III)oxide, As4O6, and organiarsenic oxides, (RAsO)n, respectively, in the presence of KI. With arsenic(III) sulphide, As4S6, and organoarsenic sulphides, (RAsS)n, thiooxarsolanes and thiooxararsenanes, respectively, are formed. Oxiranes and oxetan are supposed to be intermediates. Thiirane, C2H4S, and aziridine, C2H4NH, react, too, with (RAsO)n and (RAsS)n under mild conditions, aziridine prefereably with the sulphides.
    Notes: Cyclische Kohlensäureester, wie Äthylen-, Propylen- und Trimethylen-glykolcarbonat, lassen sich mit Arsentrioxid, As4O6, und Organoarsenoxiden, (RAsO)n, in Gegenwart geringer Mengen von Kaliumjodid unter CO2-Abspaltung zu Dioxarsolanen und Dioxarsenanen umestern. Mit Arsentrisulfid, As4S6, oder Organoarsen-sulfiden, (RAsS)n, entstehen Thioxarsolane bzw. Thioxarsenane. Als Zwischenstufen werden Oxirane und Oxetan angenommen, da diese unter Druck bei 125°C mit Arsenoxid und Arsensulfid die gleichen Substanzen bilden. Auch Thiiran, C2H4S, und Aziridin, C2H4NH, setzen sich unter milden Bedingungen mit (RAsO)n um; Aziridin reagiert vorzugsweise mit Sulfiden, weniger gut mit Oxiden.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 371 (1969), S. 193-200 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The interaction of realgar, As4S4, in N-methylaminoethanol with piperidine or hexamethyleneimine yields a piperidinium and hexamethyleneiminium salt, respectively, of the anion As4S2-6, the probable structure of which is shown in “Inhaltsübersicht”. By metathetic reactions, compounds of the approximate compositions PbAs4S6 and HgAs4S6 have been obtained. Hydrolytic cleavage of the new anion gives H2S and a crystalline residue of the analytical composition As4S5.
    Notes: Bei der Umsetzung von Realgar, As4S4, in N-Methylaminoäthanol mit Piperidin oder Hexamethylenimin entstehen ein Piperidinium- bzw. Hexamethyleniminiumsalz mit dem Anion As4S2-6. Durch doppelte Umsetzung mit Schwermetallsalzen gelingt es, Verbindungen der annähernden Zusammensetzung PbAs4S6 und HgAs4S6 zu erhalten. Das den neuen Thiosalzen zugrunde liegende Anion entsteht offenbar durch Aufspaltung einer As - As-Bindung des Realgar, während die zweite As - As-Bindung erhalten bleibt und durch disproportionierende alkalische Hydrolyse nachgewiesen werden kann. Bei der Hydrolyse in saurem Medium erhält man H2S und einen kristallinen Rückstand der analytischen Zusammensetzung As4S5. Dem Thiosalz-Anion kommt sehr wahrscheinlich folgende Struktur zu:
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 376 (1970), S. 101-106 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1.4-Chlorobutyl-dichloroarsine has been obtained by cleaving 1.4-chlorobutyl-diphenylarsine with AsCl3. Boiling with thiourea yields a thiuronium salt being hydrolysed in alkaline medium to bis-thiarsenanyl-sulphide, C8H16As2S3. From the latter, 1-chloro-2.1-thioarsenane, C4H8AsSCl, is obtained with AsCl3. Hydrolysis of 1.4-chlorobutyl-dichloroarsine gives 1.4-butanol-dichloroarsine which may be converted, by splitting off HCl, into 1-chloro-2.1-oxarsenane; this is hydrolysed to bis-oxarsenanyl-oxide, C8H16As2O3.
    Notes: 1,4-Chlorbutyl-dichlorarsin wird durch Spalten von 1,4-Chlorbutyl-diphenylarsin mit AsCl3 gewonnen. Durch Kochen mit Thioharnstoff erhält man ein Thiuroniumsalz, das bei alkalischer Hydrolyse das Bis-thioarsenanyl-sulfid, C8H16As2S3, ergibt. Hieraus erhält man mit AsCl3 1-Chlor-2,1-thiarsenan, C4H8AsSCl. Verseifen von 1,4-Chlor-butyl-dichlorarsin führt zu 1,4-Butanol-dichlorarsin, das bei HCl-Abspaltung 1-Chlor-2,1-oxarsenan liefert, welches zum Bis-oxarsenanyl-oxid, C8H16As2O3 hydrolysiert wird.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 376 (1970), S. 150-155 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1.2-ethane-bis(dichloroarsine), (CH2AsCl2)2, has been prepared from 1.2-bis(diphenylarsino)-ethane or 1.2-bis(phenylchlorosino)-ethane and arsenic trichloride at 280°C. Its solvolysis by H2O or H2S gives 1.2-ethanediarsenic oxide and -sulphide, respectively, which on reaction with AsCl3 yield 1.3-dichloro-diarsoxolane resp.-diarsthiolane. 1.2-ethanediarsenic oxide is alkylated by methyl iodide to 1.2-ethane-bis(methylarsenic acid).
    Notes: 1.2-Äthan-bis-dichlorarsin, (CH2AsCl2)2, wird aus 1.2-Bis-diphenyl-arsino-äthan oder 1.2-Bis-phenylchlorarsino-äthan und Arsentrichlorid bei 280°C dargestellt. Solvolyse mit H2O oder H2S führt zu 1.2-Äthandiarsenoxid und -sulfid, die mit AsCl3 1.3-Dichlor-diarsoxolan und 1.3-Dichlor-diarsthiolan ergeben. Methyljodid alkyliert das 1.2-Äthandiarsenoxid zu 1.2-Äthan-bis-methylarsinsäure.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 376 (1970), S. 37-43 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Triphenyl phosphine and α,ω-bis-diphenylphosphino-alkanes may be cleaved on two reaction paths. Whereas alkaline metals in various solvents split off one phenyl group, two such groups are eliminated by commutation with phosphorus trichloride at 280°C under pressure, resulting in the formation of alkane-bis-dichlorophosphines the reactions of which are described.
    Notes: Triphenylphosphin und α,ω-Bis-diphenylphosphino-alkane können auf zwei Wegen gespalten werden. Während Alkalimetalle in verschiedenen Lösungsmitteln eine Phenylgruppe ablösen, erzielt man die Abspaltung zweier Phenylreste durch Kommutieren mit Phosphortrichlorid bei 280° unter Druck. Die Eigenschaften der hierbei entstandenen α,ω-Alkan-bis-dichlorphosphine und ihre Reaktionen werden beschrieben.
    Additional Material: 4 Tab.
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