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  • 1
    ISSN: 1434-4475
    Keywords: Cinnamonitriles ; Cyanoethylations ; Heterocycles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 3-Antipyrinyl-5-aminopyrazol (1) reagierte mit Acrylnitril zu 5-Amino-1-β-cyanoethyl-3-antipyrinylpyrazol (2).2 konnte ebenfalls aus der Reaktion von β-Cyanethylhydrazin (3) und Verbindung4 erhalten werden.2 wurde mittels Essigsäure-Salzsäure glatt zu 2-Antipyrinyl-4,5,6,7-tetrahydropyrazolo[1,5-a]-pyrimidin-5-on (5) cyclisiert.5 konnte auch aus der Reaktion von1 mit Methylacrylat erhalten werden. Die Reaktion von1 mit Zimtsäurenitrilderivaten7 a–e ergab die Pyrazolo[1,5-a]pyrimidin-Derivate9,11 und12.
    Notes: Abstract 3-Antipyrinyl-5-aminopyrazole (1) reacted with acrylonitrile to afford 5-amino-1-β-cyanoethyl-3-antipyrinylpyrazole (2). Compound2 could also be obtained from the reaction of β-cyanoethylhydrazine (3) and compound4.2 was readily cyclized into 2-antipyrinyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidin-5-one (5) by acetic-hydrochloric acid.5 could be also obtained from the reaction of1 and methyl acrylate. The reaction of1 and cinnamonitrile derivatives7 a–e resulted in the formation of pyrazolo[1,5-a]pyrimidine derivatives9,11 and12.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 1081-1085 
    ISSN: 0021-8995
    Keywords: 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 , Physics
    Notes: The effect of preextension on the variation of the electrical conductivity (σ) of butyl rubber (IIR) loaded with high abrasion furance (HAF) and fast extrusion furance (FEF) carbon black with carbon concentration have been investigated. The change in σ has been explained as a result of the interaction between carbon and rubber and the effect of the occluded rubber.The effect of preextension on the electrical resistivity (ρ) variation with strain has also been studied. The changes have been interpreted as being due to either breakdown or reagglomeration, depending on the concentration of carbon black.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 12 (1989), S. 187-188 
    ISSN: 0935-6304
    Keywords: HPLC ; Derivatization ; Electrochemical detection ; Dansyl derivatives ; Fluorescence ; Amino acids ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 332 (1990), S. 640-644 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,1-Dicyanomethylene-3-indanone (2) reacted with cinnamonitriles 1a-c to afford fluorenone derivatives 6a-c. Compounds 6a-c were also obtained when treating 2 with 1d-f. The coupling of 2 with aromatic diazonium chlorides resulted in the formation of the hydrazones 8a-c. 8a readily cyclized to indeno[2,1-c]pyridazine (9a) in acidic medium. The action of 1d-f on enaminone 3 was also studied.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 129 (1985), S. 1-9 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Zwei Typen von Ruß „fast extrusion furnace black“ (FEF) und „high abrasion furnace black“ (HAF) wurden mit einer Konzentration von 50 Teilen pro 100 Teilen in Styrol/Butadien- und Naturkautschuk eingebaut. Der Einfluß der Zeit, der Alterung und der Temperatur auf die elektrische Leitfähigkeit wurde untersucht. Es zeigte sich, daß eine thermische Alterung bei 95°C zu einem Minimum in der Leitfähigkeit (σ) bei beiden Proben FEF/NR und HAF/NR führte. Dieses wurde mit einer Konkurrenzreaktion zwischen zwei Faktoren erklärt: Abbau und Anstieg der Vernetzungsdichte in der Kautschukmatrix. Im Falle von FEF/SBR und HAF/SBR zeigen diese Faktoren vergleichbare Effekte auf die Leitfähigkeit nach 10 Tagen Alterung. Aus den Strom-Spannungscharakteristiken (I-V) wurden die Trägerkonzentration, Haftstellendichte und Driftbeweglichkeit berechnet. Das für die Temperaturabhängigkeit gefundene Minimum der Leitfähigkeit von FEF/NR wird diskutiert, wobei sich herausstellte, daß sie von der relativen Größe der Kohlenstoff- und Kautschukaggregate kontrolliert wird.
    Notes: Two types of carbon black namely fast extrusion furnace black (FEF) and high abrasion furnace black (HAF) were incorporated with a concentration of 50 phr into styrene butadiene rubber (SBR) and natural rubber (NR). The effect of the time of aging and temperature on the electrical conductivity was studied. It was found that a thermal aging at 95°C leads to the appearance of minimum in conductivity (σ) in both FEF/NR and HAF/NR. This was explained by a competition between two factors: degradation and increase of crosslinking density in the rubber matrix. In case of FEF/SBR and HAF/SBR it seems that these factors have comparable effects on the conductivity after 10 days of aging. From the current-voltage (I-V) characteristics the carrier concentration, trap density, and the drift mobility were calculated. The minimum found in the temperature dependence of σ for FEF/NR is discussed and found to be controlled by the relative dimension of carbon and rubber aggregates.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 115 (1983), S. 39-46 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wurde der Einfluß von verschiedenen Additiven, die gewöhnlich bei der Herstellung von Kautschukmischungen zugesetzt werden, auf die elektrische Leitfähigkeit σ von Styrol-Butadien-Kautschuk untersucht. Es zeigte sich, daß Verarbeitungsöl (als Weichmacher) einen merklichen Anstieg von σ gegenüber der reinen Probe verursacht.Stearinsäure (als Antioxidans) jedoch zeigt keinen erheblichen Einfluß auf σ. Die Zugabe einer konstanten Konzentration von 50 Teilen auf Hundert verschiedener Typen von Ruß (als Füllstoff) wie ISAF, HAF, FEF und SRF zu der Kautschukmatrix ergab unterschiedliche Werte der Anfangsleitfähigkeit der vulkanisierten Proben. Der Leitungsmechanismus von mit Ruß gefüllten Kautschukvulkanisaten wurde diskutiert und eine grobe Abschätzung der Abstände zwischen Rußpartikeln (oder Aggregaten) vorgeschlagen. Die rußgefüllten Vulkanisate zeigten eine annehmbare Stabilität und Reproduzierbarkeit von σ nach der vor-thermisch-oxidativen Alterung bei 365 K während 30 Tagen.
    Notes: The effect of different ingredients, which are usually added during the preparation of rubber mixtures, on the electrical conductivity σ of styrene-butadiene rubber (SBR-1502) has been studied. It was found that processing oil (as softener) showed a marked increase in σ with respect to the pure sample. Stearic acid (as antioxidant), however, did not show a considerable effect on σ. The addition of constant concentration of 50 phr from different types of carbon black (filler) namely, ISAF, HAF, FEF and SRF to the rubber matrix resulted in different values of the initial conductivity of the vulcanized samples. The conduction mechanism through carbon black-loaded rubber vulcanizates has been discussed and rough estimation of the separation distance between carbon black particles (or aggregates) suggested. The carbon black-loaded rubber vulcanizates showed a reasonable stability and reproducibility of σ after pre-thermal-oxidative ageing at 365 K for 30 days.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 165 (1989), S. 69-78 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In dieser Arbeit interessieren wir uns für den Einfluß von Konzentration und Temperatur auf den elektrischen Widerstand eines Butyl-Kautschuks (IIR), der mit zwei Typen von Ruß (Hoch-Abrasion-Schmelzofen-Ruß (HAF) und Schnell-Extrusion-Hochofen-Ruß (FEF)) versetzt ist. Ergebnis war, daß die Leitfähigkeit bei niedrigem Rußgehalt hauptsächlich durch thermische Aktivierung der Ladungsträger erreicht wird. Bei mittleren Konzentrationen überwiegt der Tunnel-Mechanismus bei niedriger Temperatur, gefolgt von der thermischen Aktivierung bei relativ hoher Temperatur. Dies gilt für beide Rußarten. Das metallartige Verhalten bei Gemischen mit hoher Rußkonzentration kann sowohl der thermischen Ausdehnung der Tunnelwege zwischen Kohlenstoff-Agglomeraten als auch dem Zusammenbruch der Kohlenstoff-Agglomerate bei steigender Temperatur zugeschrieben werden.
    Notes: In this study we are interested in the effect of concentration and temperature on the electrical resistivity of butyl rubber (IIR) loaded with two types of carbon black, (namely, high abrasion furnace black (HAF), and fast extrusion furnace black (FEF)). It was found that the conductivity at low carbon black concentrations is mainly achieved by thermal activation of carriers. Tunneling mechanism at low termperature followed by thermal activation at relatively high temperature is found to be predominant for moderate concentrations for both carbon blacks. The metal-like behaviour which was observed in highly loaded compounds was attributed to both, the thermal expansion of the tunneling paths between carbon-carbon agglomerates and the breakdown of carbon agglomerates with temperature.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1989 (1989), S. 935-936 
    ISSN: 0170-2041
    Keywords: Cinnamonitriles ; Cyclopentanone ; Indene ; Cyclopentapyran ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyclopentanone reacts with arylidenemalononitriles 1a-c to give dihydro-4,6-indenedicarbonitriles 5a-c. Similarly, the diethyl dihydro-4,6-indenedicarboxylate derivative 6 is formed when treating ethyl α-cyanocinnamate (1d) with cyclopentanone. Cyclopenta[b]pyrans 5a-c are obtained from the reaction of diarylidene derivatives of cyclopentanone with malononitrile.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1990 (1990), S. 409-409 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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