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  • 1
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 59 (2000), S. 531-539 
    ISSN: 1572-8943
    Keywords: carbocationic polymerization ; char yield ; N-aryl nadimides ; ring opening metathesis polymerization (ROMP) ; thermal stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Carbocationic polymerization of N-ortho/meta/para tolyl-exo-norbornene dicarboximide (nadimide) was carried out using Pd(II) catalyst. Under similar conditions of polymerization, poly(N-m-tolyl nadimide) showed higher molecular mass compared to poly(N-p-tolyl nadimide) and poly(N-o-tolyl nadimide). Thermal stability of these polymers was evaluated by dynamic thermogravimetry in nitrogen atmosphere. The polymers were stable up to 460°C and lost mass above this temperature in a single step. The characteristic decomposition temperature and char yield of these polymers were higher than the polymers prepared by using ring opening metathesis polymerization. The difference has been attributed to the presence of rigid bicyclic ring structure in these polymers.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 2857-2866 
    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: Low molecular weight poly(p-phenylene sebacamides) and (m-phenylene sebacamides) were prepared by interfacial polycondensation by varying the concentration of p-and m-phenylenediamine in the initial feed. The polymers were characterized by intrinsic viscosity measurement and IR spectra. The relative thermal stability was evaluated by differential thermal analysis and dynamic thermogravimetry in air and nitrogen atmospheres. A systematic dependence of stability on intrinsic viscosity of poly(m-phenylene sebacamide) was observed indicating an endgroup initiation of degradation. No such dependence was observed in poly(p-phenylene sebacamide). A probable mechanism for the thermal degradation has been proposed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 2933-2938 
    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 potential of 2-hydroxyethyl methacrylate and ethyl acrylate copolymers as negative photoresists was studied. Negative photoresist solution was prepared by esterfication of copolymers with cinnamoyl chloride. The effects of photosensitizer concentration, copolymer composition, and exposure time were investigated. A resolution of 30 μm was attained from these photoresists.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 46 (1975), S. 1-10 
    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: Handelsprodukte von Polyvinylalkohol (PVA) und Polyvinylacetat (PVAc) wurden einer Fällungsfraktionierung unterworfen. Es wurden neun bzw. sechs Fraktionen erhalten. Die Abhängigkeit der thermischen Stabilität der Polymeren vom Molekulargewicht der Proben wurde thermogravimetrisch in Luft untersucht. Messungen zur Bestimmung der Abhängigkeit des Abbaugrades von der Temperatur sowie zur Bestimmung der Aktivierungsenergie ergaben eine direkte Proportionalität zwischen der Stabilität von PVAc und dem Molekulargewicht der Probe. Für PVA wurde ein Molekulargewichtsbereich ermittelt, für den eine maximale thermische Stabilität besteht. Sowohl für höhere als auch für niedrigere Molekulargewichte war diese Stabilität geringer.
    Notes: The commercially available poly(vinyl alcohol) (PVA) and poly(vinyl acetate) (PVAc) were fractionated by precipitation to give nine and six fractions respectively. The dependence of the thermal stability of the polymer on the molecular weight of the samples was investigated by dynamic thermogravimetry in air. The percentage decomposition temperature, integral procedural decomposition temperature, and activation energy measurements revealed that the stability of PVAc was directly proportional to the molecular weight of the sample. In PVA, there was an optimum polymer size where the stability was at a maximum, and it decreased on increasing or decreasing the molecular weights.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 55 (1976), S. 109-116 
    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: Die Kohäsionsenergiedichten (c.e.d.) der Copolymerisate verschiedener Zusammensetzungen aus 2-Hydroxyäthylmethacrylat (HEMA) und Methylacrylat (MA) wurden durch Quellungsmessungen bestimmt. Es zeigte sich, daß die c.e.d. abnimmt, wenn der Gehalt an 2-Hydroxyäthylmethacrylat im Copolymeren vergrößert wird.
    Notes: The cohesive energy densities (c.e.d.) of copolymers having varying compositions of 2-hydroxyethylmethacrylate (HEMA) and methylacrylate (MA) were determined from swelling measurements. It was found that the c.e.d. decreases as the 2-hydroxyethylmethacrylate content increases in the copolymer.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 71 (1978), S. 157-166 
    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: Der Einfluß von Additiven (Maleinsäureanhydrid, p-Benzochinon, 9,10-Anthrachinon) auf die HCl-Abspaltungsgeschwindigkeit von PVC in Äthylbenzoat im Temperaturbereich zwischen 180° bis 210°C wird untersucht. Bei Temperaturen ab 200°C wird in Anwesenheit der Additive eine Verringerung der Geschwindigkeit beobachtet. Für diese Stabilisierung wird ein Mechanismus vorgeschlagen.
    Notes: The effect of additives (maleic anhydride, p-benzoquinone and 9,10-anthraquinone) on the rate of dehydrochlorination of PVC in ethyl benzoate was investigated at temperatures ranging from 180° to 210°C. A reduction in the rates was observed in presence of these additives at 200°C and above. A mechanism has been proposed to account for the stabilization effect.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 79 (1979), S. 147-155 
    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: Veränderungen der Molekulargewichte und der Molekulargewichtsverteilung von PVC, das in Gegenwart von Maleinsäureanhydrid, Benzochinon oder Anthrachinon abgebaut wurde, wurden durch Gelchromatographie untersucht. Ketten-Spaltungs- und Vernetzungsreaktionen waren durch den M̄w und M̄n-Wert zu erkennen. In Gegenwart von Anthrachinon waren Vernetzungsreaktionen vorherrschend.
    Notes: The changes in molecular weight and molecular weight distribution of PVC degraded in presence of maleic anhydride, benzoquinone and anthraquinone were studied by gel permeation chromatography. Chain scission and crosslinking reactions were indicated on the basis of M̄n and M̄w of degraded samples. Crosslinking was predominant when degradation was carried out in presence of anthraquinone.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 80 (1979), S. 119-127 
    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: Zahlreiche Copolymere mit Benzimidazolringen, Alkylen- und Arylengruppen in der Kette wurden aus 3,3′-Diaminobenzidintetrahydrochlorid-dihydrat und Dicarbonsäuren in Polyphosphorsäure hergestellt. Die Viskositätszahlen dieser Polymeren in conc. H2SO4 wurden bei 30, 40 und 50°C bestimmt. Es wurde kein systematischer Gang der Huggins-Konstante mit der Temperatur gefunden. Q- und A-Werte der Gleichung η = A · exp(Q/RT) wurden für diese Polymeren in H2SO4 bestimmt. Aus den A-Werten wurde geschlossen, daß die meisten Polymeren steife Ketten bilden, mit Ausnahme derer, die cis-Vinylengruppen in der Kette enthalten.
    Notes: Various copolymers having benzimidazole rings along with alkylene and arylene groups in the backbone were prepared from 3,3′-diaminobenzidine tetrahydrochloride dihydrate and dicarboxylic acids in polyphosphoric acid. The viscosities of these polymers in concentrated sulphuric acid (98%) have been determined at 30, 40 and 50°C. There is no systematic variation in the value of K′ (Huggins constant) with temperature. Values of Q and A in the expression η = A exp(Q/RT) were obtained for these polymer samples in H2SO4. On the basis of the ‘A’ values, it has been concluded that most of these polymers were stiff chains with the exception of those containing cis-vinylene groups in the backbone.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 46 (1975), S. 11-21 
    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: Der thermische Abbau von Polyvinylacetat wurde in Äthylbenzoat, Benzylbenzoat und Äthylsalicylat unter Stickstoff im Temperaturbereich zwischen 189 und 212°C untersucht. Der Abbau wurde durch Titration der ausgeschiedenen Säure und an Absorptionsspektren vom abgebauten Polymeren verfolgt. Er wurde durch die Lösungsmittel beeinflußt; er war in Äthylsalicylat stärker als in den anderen Lösungsmitteln. Eine breite Absorptionsbande wurde in Benzylbenzoat und Äthylbenzoat gefunden, während in Äthylsalicylat Peaks bei 367, 390, 412 und 435 nm beobachtet wurden. Polyene mit kleiner Zahl von Doppelbindungen waren gegenüber Polyenen mit mehr als 10 Doppelbindungen dominant. Die Aktivierungsenergie für den Abbau lag in diesen Lösungsmitteln zwischen 11 und 15 kcal/mol. Die Ergebnisse werden diskutiert unter Annahme einer Mitwirkung der Lösungsmittel beim Abbauprozeß.
    Notes: The thermal degradation of poly(vinyl acetate) in ethyl benzoate, benzyl benzoate, and ethyl salicylate was investigated in an atmosphere of nitrogen in the temperature range 189-212°C. The degradation was followed by titrating the evolved acid and recording the absorption spectra of the degraded polymer solution. The degradation was influenced by the solvents, and was higher in ethyl salicylate than in other solvents. A broad absorption band was observed in benzyl benzoate and ethyl benzoate while in ethyl salicylate peaks at 367, 390, 412, and 435 nm were observed. Polyenes with a smaller number of double bonds were more predominant than polyenes having more than 10 double bonds. The activation energy varied between 11-15 kcal/mol in these solvents. The results have been explained by proposing the participation of solvents in the degradation reactions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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