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  • 1
    ISSN: 1434-4475
    Keywords: 2(2-Hydroxyphenyl)2H-benzotriazole ; Polymerizable stabilizers ; Ultraviolet spectra
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung 2(2,4-Dihydroxyphenyl)2H-benzotriazol wurde mit 50% Ausbeute über die Kondensation vono-Nitrobenzoldiazoniumchlorid mit Resorcin, gefolgt von reduktiver Cyclisierung der ursprünglich erhaltenen Azoverbindung mit Zn/NaOH, erhalten. Die Kondensation des Diazonium-Salzes hatte unter sorgfältig kontrollierten Bedingungen und im sauren Medium zu erfolgen, da ansonsten „Bis“-Kondensation auftrat, die nach der reduktiven Cyclisierung 2(2,4-Dihydroxyphenyl)1,3-2H-dibenzotriazol ergab. 2(2,4-Dihydroxyphenyl)2H-benzotriazol wurde mit Acryoyl- bzw. Methacryloylchlorid zur Reaktion gebracht, wobei die Monoacetylierungsprodukte in über 60% Ausbeute gewonnen wurden. Die beiden Monomeren wurden homopolymerisiert und mit Styrol, Methylmethacrylat undn-Butylacrylat zu Polymeren hohen Molekulargewichts copolymerisiert. Die Inkorporierung von 2[2-Hydroxy-4-acryloxy (bzw. 4-methacryloxy)]2H-benzotriazol in das Copolymer erfolgte zwischen 1 und 10 mol% der Comonomer-Mischung. Die UV-Spektren der Monomeren, Homo- und Copolymeren sind angegeben.
    Notes: Abstract 2(2,4-Dihydroxyphenyl)2H-benzotriazole has been prepared in about 50% yield by condensation ofo-nitrobenzenediazonium chloride with resorcinol followed by reductive cyclization of the initially obtained azo compound with zinc and sodium hydroxide. The condensation of the diazonium salt had to be carried out under carefully controlled conditions and in acidic medium, otherwise “bis”-condensation occurred which, after reductive cyclization, yielded 2(2,4-dihydroxyphenyl)1,3-2H-dibenzotriazole. 2(2,4-Dihydroxyphenyl)2H-benzotriazole was allowed to react with acryloyl or methacryloyl chloride. Monoacylation in the 4-position occurred by interfacial acylation technique and 2[2-hydroxy-4-acryloxy (or 4-methacryloxy)]2H-benzotriazole was obtained in over 60% yield. The two monomers were homopolymerized and copolymerized with styrene, methyl methacrylate, andn-butyl acrylate to polymers of high molecular weight. Incorporation of 2[2-hydroxy-4-acryloxy (or 4-methacryloxy)]2H-benzotriazole into the copolymer was from 1 to 10 mol% of the comonomer mixture. The ultraviolet spectra of monomers, homo- and copolymers were also determined.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 265-279 
    ISSN: 0887-624X
    Keywords: 1,3-dioxan-2-one ; oxepan-2-one ; copolymer ; characterization ; coordination catalysits ; initiation mechanism ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new type of copolymer is synthesized in a bulk polymerization from 1,3-dioxan-2-one and oxepan-2-one (∊-caprolactone) using either Sn-oct, ZnAc2, Bu2SnO, or Bu3SnCl as the catalyst. SEC analysis shows that it is possible to achieve high molecular weights and narrow molecular weight distributions. 13C-NMR analysis confirms the existence of copolymers. Conversion studies have been made and reactivity ratios, r1 and r2, have been determined to distinguish between the reactivities of 1,3-dioxan-2-one and oxepan-2-one. The Finemann-Ross method and the Kelen-Tüdös method were used to calculate the ratios and the agreement was good between the methods. The composition of the copolymer agrees with the feed composition at high conversions. Thermal analysis of copolymers by DSC shows crystalline melting resulting from a somewhat blocky copolymer. The glass transition temperatures of the copolymers are in agreement with the Fox equation. The corresponding blends of the two homopolymers show a constant melting point and glass transition temperature. A nonionic insertion mechanism and a Lewis acid alcoholysis mechanism are discussed. © 1994 John Wiley & Sons, Inc.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
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