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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 124 (1993), S. 217-227 
    ISSN: 1434-4475
    Keywords: Isotropic solids ; Optical activity ; Sodium bromate ; Sodium chlorate ; Suspension measurements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wurde eine verläßliche Methode zur Messung der optischen Aktivität isotroper Verbindungen in Suspensionen unter Verwendung zweier mischbarer Flüssigkeiten als Medium zur Suspension feiner Pulver entwickelt. Die optische Rotation wurde nach einer präzisen Anpassung des Brechungsindex des Suspensionsmediums an den der Festpartikel gemessen. Zur Entwicklung der Methode wurden Natriumchlorat und Natriumbromat als Festkörper eingesetzt. Die Messungen waren in perfekter Übereinstimmung mit Rotationswerten aus entsprechenden großen Kristallen.
    Notes: Summary A reliable method for the measurement of the optical activity of optically active isotropic solid substances in suspension was developed using two miscible liquids as media for suspending the fine solid powders. The optical rotation was measured after precise matching of the refractive index of the suspending media with that of the solid particles. Sodium chlorate and sodium bromate were used as optically active solids for the development of this method. The measurements were in complete agreement with the measurements of the optical rotation of the corresponding large crystals.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1434-4475
    Keywords: Benzotriazole formation ; N M R-structure analysis ; Polymerization and copolymerization ; Ultraviolet absorbers ; 2[2-Vinyl-4-hydroxyphenyl]2H-benzotriazole ; 2[3-Vinyl-4-hydroxyphenyl]2H-benzotriazole
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Diazotierteso-Nitroanilin wurde mit 3-Ethylphenol bzw. mit 2-Ethylphenol kondensiert. Reduktion der Diazoverbindung mit Zinkstaub in Natriumhydroxid ergab 2-(2-Ethyl-4-hydroylphenyl)2H-benzotriazol, bzw. 2-(3-Ethyl-4-hydroxyphenyl)2H-benzotriazol. Nach Acetylierung der freien Phenolgruppe wurden diese Verbindungen mitN-Bromsuccinimid zu den entsprechenden1-Bromethylverbindungen umgewandelt und daraufhin in Acetonitril mit Triethylamin dehydrobromiert. Darauf folgende Hydrolyse führte zu 2(2-Vinyl-4-hydroxyphenyl)2H-benzotriazol bzw. zu 2(3-Vinyl-4-hydroxyphenyl)2H-benzotriazol. Beide monomeren Verbindungen wurden sowohl homopolymerisiert als auch mit Styrol oder mit Methylmethacrylat copolymerisiert. Weder die Ethyl- noch die Vinylverbindungen oder deren Polymere erwiesen sich als UV-Stabilisatoren, eine Eigenschaft die den 2(2-Hydroxyphenyl)2H-Benzotriazolen eigen ist. Eine Methode der Strukturbestimmung mit Hilfe einer detaillierten NMR-Analyse wird ebenfalls beschrieben.
    Notes: Abstract Condensation of diazotizedo-nitroaniline with 3-ethylphenol or with 2-ethylphenol followed by reduction of the resulting azo compound with zinc dust in sodium hydroxide solution gave 2-(2-ethyl-4-hydroxyphenyl)2H-benzotriazole and 2(3-ethyl-4-hydroxyphenyl)2H-benzotriazole, respectively. The individual compounds were acetylated, brominated withN-bromosuccinimide to the corresponding 1-bromoethyl compounds which were then dehydrobrominated with triethyl amine in acetonitrile and hydrolyzed to 2(2-vinyl-4-hydroxyphenyl)2H-benzotriazole or 2(3-vinyl-4-hydroxyphenyl)2H-benzotriazole. The two monomers could be polymerized and copolymerized with styrene and methyl methacrylate. The ethyl as well as the vinyl compounds and the corresponding polymers, when tested, are ineffective as ultraviolet absorbers as they have structures of 4-hydroxyphenyl rather than 2-hydroxyphenyl compounds with respect to the benzotriazole ring. A careful NMR analysis for the correct structural assignment is also described.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 121 (1990), S. 311-316 
    ISSN: 1434-4475
    Keywords: Solid state measurement ; Optical rotation ; Powder-suspension ; Sodium chlorate ; RNA ; Synthetic polymers ; Biopolymers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Es wird über eine Methode zur Messung der optischen Rotation von Festkörpern in Suspensionen berichtet, wobei dissymetrische Kristalle (z. B. Natriumchlorat und -bromat), synthetische Polymere, Polypeptide und Biopolymere behandelt werden. Die Beispiele umfassen Poly(triphenylmethylmethacrylat), Poly-S-lactid, Poly-L-hydroxyprolin, Hemocyanin, Celluloseacetat undRNA. Die Ergebnisse zeigen, daß die optischen Rotationen bezüglich Unterschiede in der Sekundärstruktur empfindlich sind und daß diese Messungen als ein Maß für Strukturunterschiede zwischen Festzustand und Lösung herangezogen werden können.
    Notes: Summary We report techniques for measuring optical rotation of suspended solids, including dissymmetric molecular crystals (e.g. sodium chlorate and bromate), synthetic polymers, polypeptides and biopolymers. Examples include poly(triphenylmethyl methacrylate), poly-S-lactide, poly-L-hydroxyproline, hemocyanine, cellulose acetate andRNA. The results indicate that optical rotation measurements are sensitive to differences in secondary structure and can serve as a probe for structural differences between solid-state and solution.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of 2(2-hydroxy-5-methylphenyl)-5-vinyl-2H-benzotriazole was accomplished in seven steps starting from 4-ethylaniline. Acetylation and nitration followed by hydrolysis gave 2-nitro-4-cthylaniline which was diazotized, condensed with p-cresol, and reduced to 2(2-hydroxy-5-methylphenyl)-5-ethyl-2H-benzotriazole. As in previous cases, the ethyl group was transformed to the vinyl compound by bromination with N-bromosuccinimide and dehydrobromination of the 1-bromoethyl compound. Monomer grade 2(2-hydroxy-5-methylphenyl)-5-vinyl-2H-benzotriazole was polymerized and copolymerized with styrene, methyl methacrylate, and n-butyl acrylate.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Successful grafting of 2(2-hydroxy-5-vinylphenyl)2H-benzotriazole onto saturated aliphatic C—H groups of polymers has been accomplished. When the grafting reaction was carried out in chlorobenzene at 150-160°C with di-tertiary butylperoxide as the grafting initiator, grafts as high as 20-30% at grafting efficiencies of 50 and 80% have readily been obtained. It was very important to carry out the grafting reaction in tubes sealed under high vacuum since trace amounts of oxygen cause complete inhibition of the grafting reaction by the phenolic monomer. Grafting reactions were carried out on a variety of different polymers including atactic polypropylene, ethylene/vinyl acetate copolymer, poly(methyl methacrylate), poly(butyl acrylate), and polycarbonate.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 2629-2648 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Head-to-head polyisobutylene of molecular weight 3000 to 10,000 was prepared in about 30% yield by Grignard coupling polymerization of 2,2,3,3-tetramethyl-1,4-dibromobutane with copper(I) tris(triphenylphosphino)bromide as the catalyst. Head-to-head polyisobutylene is crystalline, with a Tm of 187°C and a Tg of 87°C and still has bromine end groups left. The polymers have been characterized by their infrared, 1H-, and 13C-NMR spectra and compared to the corresponding head-to-tail polymers of similar molecular weight. A substantial portion of the reaction product of the Grignard coupling polymerization is not polymeric but was identified as cyclized product, 1,1,2,2-tetramethylcyclobutane.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 2713-2725 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acrylonitrile was terpolymerized with styrene and 2,4,6-tribromophenyl acrylate in aqueous emulsion and dimethylformamide solution. Experimental terpolymerization data agreed well with calculations based on the Alfrey-Goldfinger equation. Triangular coordinate graphs show the feed/terpolymer relationships; the lines of unique and binary azeotropic compositions were identified. No points of true azeotropic composition were found but a “pseudo-azeotropic” region was recognized. The experimental data of the emulsion terpolymerization experiment agreed well with the theoretical curves over a wide range of monomer compositions up to high conversions. Incorporation of 2,4,6-tribromophenyl acrylate in the terpolymer decreased the thermal stability but improved the flame retardancy of the terpolymers.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 21 (1983), S. 1913-1928 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The terpolymerization of acrylonitrile with styrene and 2,3-dibromopropyl acrylate in emulsion and dimethyl formamide solution was investigated. Polymerizations, when stopped at low conversions, yielded terpolymers that showed good agreement between experimental and theoretical copolymerization composition data, calculated from the Alfrey-Goldfinger equation. The relationship between monomer feed and terpolymer compositions is displayed on triangular coordinate graphs proposed by Slocombe. By using a computer program the lines of unique composition and binary azeotropic composition for both systems were established. In the case of emulsion polymerization the azeotropic ternary point was determined at a molar ratio for acrylonitrile/styrene/2,3-dibromopropyl acrylate of 0.27/0.61/0.12. The experimental results of emulsion terpolymerization fit the calculated curves satisfactorily over a wide range of monomer compositions up to high conversions. The influence of 2,3-dibromopropyl acrylate on the thermal and flammability characteristics of the terpolymers is described.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 2501-2521 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ω-Alkenoic acids, either commercially available or synthesized, were esterified to their corresponding methyl esters. They were characterized by their infrared, 1H-, and 13C-NMR spectra. The ω-alkenoates prepared were: propenoate (acrylic acid), butenoate, pentenoate, hexenoate, heptenoate, octenoate, nonenoate, and decenoate. These compounds were epoxidized with m-chloroperoxybenzoic acid to the corresponding methyl ω-epoxyalkanoates. The rate of epoxidation of the double bond is found to increase as the double bond is separated from the carbomethoxy group by increasing numbers of methylene groups. When at least three methylene groups are inserted, the rate of epoxidation becomes constant and is similar to the epoxidation of ω-olefins. The methyl ω-epoxyalkanoates were characterized by their infrared, 1H-, and 13C-NMR spectra. Methyl ω-alkenoates and methyl ω-epoxyalkanoates were prepared and characterized, and their purification was studied in preparation for their investigation as monomers for olefin or epoxide polymerization using corrdination initiators.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 20 (1982), S. 2477-2499 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Biuret oligomers and polymers from primary aliphatic amines and aromatic or aliphatic diisocyanates have been synthesized. To demonstrate the feasibility of the synthesis of polybiurets, aliphatic primary amines with n-propyl, n-hexyl, n-octyl, and n-dodecyl groups have been incorporated. For the synthesis of biuret oligomers of biologically active primary aliphatic amines [8-(4-amino-1-methylbutylamino)-6-methoxyquinoline] (primaquine) and adamantanamine were selected. Primaquine was also incorporated into polyepichlorohydrin by nucleophilic substitution of the chlorine of the chloromethyl group by the primary aliphatic amino group of primaquine. The structure of the biuret polymers was established by elemental analysis, and by infrared 1H- and 13C-NMR spectroscopic characterization. Several attempts to use primaquine as a diamine for the formation of condensation polymers, including reaction of primaquine with sebacoyl chloride (to form polyamides), or with diisocyanates (to form polyureas) were unsuccessful.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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