ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wird über den Beginn einer Untersuchung zur Kristallisationskinetik von Polycaprolacton (Poly(1-oxy-6-oxohexamethylene) (1)) berichtet. Die primäre Keimbildung und das primäre Sphärolith-Wachstum aus der Polymerschmelze werden bei hinreichend hohen Temperaturen verfolgt, wodurch sichergestellt ist, daß das Wachstum der Kristallite durch Keimbildung bestimmt ist. Die kinetischen Daten werden weitgehend mit Hilfe des Avrami-Modells interpretiert, welches sich gut auf die Kristallisation von 1 anwenden ließ.
    Notes: A kinetic crystallization study of polycaprolactone (poly(1-oxy-6-oxohexamethylene) (1)) has been initiated to investigate the primary nucleation and primary spherulitic growth from a polymer melt at temperatures that are high enough to insure nucleation-limited crystallite growth. The analysis of the kinetic data is largely made on the basis of an Avrami model which proved to be well suited for the interpretation of the crystallization of 1.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1705-1719 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The temperature dependence of relative modulus observed in filled thermoset, thermoplastic, and polyelectrolyte salt matrices is explained on the basis of induced stresses produced by the differences in the thermal expansion coefficients of the constituent materials. The analysis is based on the assumption that the modulus of the matrix in a filled polymer is less than that of the unfilled polymer. The temperature dependence of relative modulus is expressed as a function of the difference in thermal expansion coefficients, the volume fraction, the relative modulus in the unstressed state, and mechanical properties of the phases. Agreement is good between the analysis and experimental results for three systems: epoxy and glass, polyethylene and wollastonite, and a polyelectrolyte salt with mica and asbestos.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 45 (1992), S. 1783-1788 
    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: A procedure is described for preparing fairly uniform spheres of three different nylon polymers by phase separation. The mean diameter and polydisperse index were 5 μm and 1.056 for Griltex nylon, 5.7 μm and 1.046 for nylon 6/6, and 12.9 μm and 1.016 for nylon 6. The phase separation is done by taking a 1 wt % solution in a theta solvent above the theta temperature and cooling it rapidly. The spheres of the three nylons have various degrees of roughness. Formation of highly uniform particles during phase separation is discussed in a preliminary way. © 1992 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 58 (1995), S. 291-296 
    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 “three-liquid” contact angle procedure of Good et al. was applied to polymer films of varying Lewis acidic and basic nature to test the procedure. Surface energy parameters with the units of mJ/m2 are determined for the surfaces. These are γLWs (Lifshitz-van der Waals or apolar), γ+s (acidic), and γ-s (basic). Very little has yet been published on this new method, and this study found it to be promising. More research on the procedure is warranted. The study included films of basic polymethylmethacrylate (PMMA), and predominately acidic chlorinated polyvinylchloride (CPVC) and polyvinylfluoride (PVF) as well as the series: polyethylene (PE) and PE copolymerized with 1.8% and 7.0% acrylic acid. In some of the experiments receding contact angles were measured, and the surface energy parameters determined in order to cast more light on the mechanism of contact angle hysteresis. © 1995 John Wiley & Sons, Inc.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Systems of Salts and Mixed Solvents. XXXIV. 27Al and 1H N.M.R. Spectroscopic Investigations of AlCl3-Water-N,N-Dimethylformamide SolutionsAl3+ ions exist in aqueous solutions as well as in DMF solutions in a sixfold coordination; the coordination of DMF exclusively occurs via the oxygen atom. Because of the small shift difference between the pure aqueous and the pure DMF solution at the 27Al n.m.r. spectra no separated signals were found corresponding to the species with mixed coordination. From the changes of the Al chemical shifts and of the linewidths in dependence of the solvent composition a selective solvation process is suggested. At the 1H n.m.r. spectra for the formyl and methyl protons of DMF separated signals appear for the molecules of the first coordination sphere and of the bulk, respectively. From this the number of directly coordinated DMF molecules can be determined. Up to a DMF content of about x = 0.45 DMF is preferentially coordinated, after that a change of selectivity takes place and accordingly water is preferred at the first coordination sphere.
    Notes: Al3+-Ionen werden sowohl in wäßrigen als auch in DMF-Lösungen sechsfach koordiniert, die Koordination des DMF erfolgt über Sauerstoff. Wegen der geringen Verschiebungsdifferenz zwischen der reinen wäßrigen und der reinen DMF-Lösung treten in den 27Al-NMR-Spektren mit gemischtem Lösungsmittel keine getrennten Signale für gemischt-koordinierte Spezies auf. Aus den Änderungen der Al-chemischen Verschiebung und der Halbwertsbreite der Signale in Abhängigkeit von der Lösungsmittelzusammensetzung werden Hinweise auf eine selektive Solvatation erhalten. In den 1H-NMR-Spektren erscheinen für die Formyl- und Methylprotonen des DMF getrennte Signale für die Moleküle in der ersten Koordinationssphäre und die des restlichen Lösungsmittels. Daraus läßt sich die Anzahl der direkt koordinierten DMF-Moleküle ermitteln. Bis zu einem DMF-Gehalt von x s≈ 0,45 wird bevorzugt DMF koordiniert, danach tritt ein Selektivitätswechsel auf, so daß bevorzugt Wasser koordiniert wird.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 544 (1987), S. 225-231 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N.M.R. Investigations of Fluorodiazadiphosphetidines and Fluoro-λ5-monophosphazenesThe 19F and 31P n.m.r. data of 37 fluorodiazadiphosphetidines [RR′PF—NC6H4X]2, and 62 fluoro-λ5-monophosphazenes, RR′PF=NC6H4X, are submitted. In the case of tetrafluorodiazadiphosphetidines, [RPF2—NC6H4X]2, an intramolecular exchange of the fluorine atoms at phosphorus has to be concluded from the n.m.r. data. The influence of the substituents R and X on the n.m.r. parameters is discussed using simple models of molecular structure.
    Notes: Es werden die 19F- und 31P-NMR-Daten von 37 Fluorodiazadiphosphetidinen, [RR′PF—NC6H4X]2, und 62 Fluoro-λ5-monophosphazenen, RR′PF=NC6H4X, mitgeteilt. Aus ihnen muß für die Tetrafluorodiazadiphosphetidine, [RPF2—NC6H4X]2, auf einen intramolekularen Positionswechsel der Fluoratome am Phosphor geschlossen werden. Der Einfluß der Substituenten R und X auf die NMR-Parameter wird anhand einfacher Modelle der Molekülstruktur diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Systems of Salts and Mixed Solvents. XXXVI. 1H and 27Al N.M.R. Spectroscopic Investigations of the Solvation Behaviour in Concentrated AlCl3-Water-Alcohol Solutions1H. n.m.r. spectroscopic investigations in dependence on the solvent composition and the salt concentration are useful for the characterization of solvation processes in concentrated solutions of AlCl3-water-methanol, -ethanol, -ethylene glycol, and -diethylene glycol. In these systems water is preferentially coordinated at the first coordination sphere of the Al3+ ion within the whole region of the solvent composition.The nature of the solvation species has been investigated using 27Al n.m.r. spectroscopy. In order to reduce the „solid-type“ interactions in the concentrated solutions the Magic Angle Spinning method (MAS) was used. Particularly water-poor and water-free solutions produce structured 27Al-Mas-signals. For the system AlCl3-water-ethanol an identification of solvation species is given.
    Notes: Durch 1H-NMR-Untersuchungen in Abhängigkeit von der Lösungsmittel-zusammensetzung und der Salzkonzentration werden Solvatationsprozesse in konzentrierten Lösungen von AlCl3-Wasser-Methanol, -Ethanol, -Ethylenglycol und -Diethylenglycol näher charakterisiert. Es wird jeweils eine bevorzugte Solvatation des Al3+-Ions durch Wasser über den gesamten Zusammensetzungsbereich der Lösungsmittel festgestellt.27Al-NMR-Untersuchungen dienen zur Identifizierung von Solvatationsspezies. Zur Reduzierung der festkörperähnlichen Wechselwirkungen in den konzentrierten Elektrolytlösungen wurde die Methode der schnellen Probenrotation um den „magischen“ Winkel (MAS) eingesetzt. Insbesondere wasserarme und wasserfreie Lösungen der Systeme zeigen strukturierte 27Al-MAS-Signale. Im System AlCl3-Wasser-Ethanol wird eine Identifizierung von Solvatationsspezies vorgenommen.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-Methyl-N-Diethoxyphosphorylamido Derivatives of Hexachlorocyclotriphosphazatriene. I. The Reaction of Hexachlorocyclotriphosphazatriene with Sodium N-Methylamidophosphoric Acid Diethyl Ester.The reaction of hexachlorocyclotriphosphazatriene with the sodium salt of 0, 0-diethyl-N-methylamido-phosphate in the molar ratios 1:1, 1:2, and 1:3 gives a mixture of partially substituted compounds. The N-methyl-N-diethoxyphosphorylamidoderivatives, N3P3Cl6-n[NCH3P(O)(OC2H5)]n (n = 1, 2, 3) were isolated in a pure form by preparative column chromatography. Compounds with a higher degree of substitution are not formed. The compounds are characterized by their molecular weights, elementary analysis, and TLC-Rf values.
    Notes: Die Reaktion von Hexachlorocyclotriphosphazatrien mit dem Natriumsalz des N-Methylamidophosphorsäurediäthylesters führt bei Raumtemperatur in den Molverhältnissen 1:1, 1:2 und 1:3 zu einem Gemisch partiell substituierter Verbindungen. Mit Hilfe der präparativen Säulenchromatographie konnten die N-Methyl-N-diäthoxyphosphorylamido-Derivate, N3P3Cl6-n[NCH3P(O)(OC2H5)2]n (n = 1, 2, 3); in reiner Form isoliert werden. Verbindungen höheren Substitutionsgrades wurden nicht erhalten. Die Verbindungen wurden durch ihre Molmassen, Elementaranalysen und die dünnschichtchromatographischen Rf-Werte charakterisiert und gesichert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-Methyl-N-Diethoxyphosphorylamido Derivatives of Hexachlorocyclotriphosphazatriene. II. Ammonoloyses of N-Methyl-N-Diethoxyphosphorylamido-ChlorocyclotriphosphazatrienesMonokis-[N-methyl-N-diethroxyphosphorylamido]-pentachloro-cyclotriphospha-zatriene and 2, 4-bis-[N-methyl-N-diethoxyphosphorylamido]-2, 4, 6, 6-tetrachloro-cyclotriphosphazatriene react with gaseous ammonia at room temperature to the corresponding diamino compounds, N3P3CL4-n[NCH3P(O)(OC2H5)2]n(NH2)2, (n = 1, 2). Total Exchange of the chlorine in the N-Methyl-Ndiethoxyphosphorylamido-derivatives, N3P3CL6-n[NCH3P(O)(OC2H5)2]n, (n = a, 2, 3), takes place during the reaction with liquid ammonia. Aminophosphazenes of the type N3P3[NCH3P(O)(OC2H5)2]n(NH2)6-n, (n = 1, 2, 3), are formed. The described aminocyclotriphosphazatrienes are characterized by their melting points, elementary analyses, molecular weights and the TLC-Rf-values.
    Notes: Monokis-[N-methyl-N-diäthoxyphorylamido]-pentachloro-cyclotriphosphazatrien und 2, 4-Bis-[N-methyl-N-diäthoxyphosphorylamido]-2,4,6,6-tetrachlorocyclotriphosphazatrien reagieren mit gasförmigem Ammoniak bei Raumtemperatur zu den entsprechenden diaminoverbindungen, N3P3CL4-n[NCH3P(O)(OC2H5)2]n(NH2)2, (n = 1, 2). Vollständiger Austausch des Chlors in den N-Methyl-N-diäthoxyphosphorylamido-Derivaten, S3P3CL6-n[NCH3P(O). (OC2H5)2]n, (n = 1, 2, 3). findet bei der Umsetzung mit flüssigem ammonial Statt. Es werden dabei Aminocyclophosphazene des Typs N3P[NCH33P(O)(OC2H5)2]n(NH2)6-n, (n = 1. 2. 3) gebildet, Die beschriebenen Aminocyclophosphazatriene werden durch ihre Schmelzpunkte, Elementaranalysen, Molmassen und die dünnschichtchromatographischen Rf-Werte charakterisiert.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Temperature Dependence Investigations of 31P Chemical Shifts of Trialkoxyphosphazene N-phosphoryldialkylestersThe 31P NMR spectra of a series of trialkoxyphosphazene-N-phosphoryldialkylesters, (RO)3P=N—P(O)(OR′)2, where R = R′ = Et; R = Et, R′ = Bu; R = Bu, R′ = Et; R = R′ = Bu; and R = R = R′ = Hex respectively, and of trichlorophosphazene-N-phosphoryldichloride were investigated at various temperatures. The temperature dependence of chemical shift of phosphorus belonging to the phosphazene group is multiplicately larger than that of phosphorus belonging to the phosphoryl group. This fact also could be confirmed for other simple phosphazene and phosphoryl compounds. As discussed this different temperature dependence of 31P chemical shift is not a consequence of the medium but of the molecular structure.
    Notes: Für eine Reihe von Trialkoxyphosphazen-N-phosphoryldialkylestern, (PO)3P=N—P(O)(OR′)2, wobei R = R′ = Et; R = Et, R′ = Bu; R = Bu, R′ = Et; R = R′ = Bu bzw. R = R′ = Hex waren, sowie für Trichlorphosphazen-N-phosphoryldichlorid wurden jeweils 31P-NMR-Spektren bei verschiedenen Temperaturen aufgenommen. Es zeigte sich, daß die Temperaturabhängigkeit der chemischen Verschiebung für den Phosphor der Phosphazen-Gruppierung um ein mehrfaches größer ist als die für den Phosphor der Phosphoryl-Gruppierung. Dies konnte auch allgemein für andere einfache Phosphazen- und Phosphoryl-Verbindungen bestätigt werden. Es wird diskutiert. daß diese unterschiedliche Temperaturabhängigkeit der 31P-chemischen Verschiebung nicht auf Medieneinflüsse, sondern auf die molekulare Struktur zurückzuführen ist.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...