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  • 1
    ISSN: 0887-624X
    Keywords: fotopolymerization ; free radical polymerization ; furfuryl acrylate ; furfuryl methacrylate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect and the participation of the furfuryl ring, in particular the hydrogen at position C-5 in the free radical polymerization are analyzed following the polymerization of furfuryl acrylate (FA) and furfuryl methacrylate (FM) initiated by AIBN under photochemical activation. The results obtained indicate that the polymerization of FA deviates from the classical free radical kinetic scheme, giving rise to crosslinked polymers even at a degree of conversion lower than 7%. This behavior is well explained taking into consideration the participation of the furfuryl ring which acts as a degradative transfer agent. This was demonstrated by the kinetic analysis of the free radical polymerization of MMA initiated by the thermal decomposition of AIBN in the presence of different concentrations of furfuryl acetate. © 1996 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
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  • 2
    ISSN: 0935-9648
    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
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0887-624X
    Keywords: photopolymerization ; copolymers ; hydrogels ; biocompatible polymers ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The study of the homo- and copolymerization of furfuryl methacrylate (F) and vinylpyrrolidone (P) in bulk, initiated by the photoactivation of AIBN at low temperatures (0 and 40°C), is described. The kinetic diagrams for the homopolymerization of F and P were obtained following the evolution of the heat of reaction by DSC, and revealed the autoacceleration and the vitrification effects on the polymerization rate. The influence of oxygen in the photoinitiated polymerization was analyzed by determining the steady-state concentration of oxygen from the kinetic data obtained for polymerizations performed out in the presence and absence of oxygen. The results obtained indicate that P is more sensitive than F to the presence of oxygen in free radical polymerization. The photoinitiated copolymerization process is little affected by the concentration of monomers, giving similar Rp and θm values for both systems. However, at low polymerization temperature 0°C non-crosslinked copolymers are obtained, whereas at a temperature of 40°C, the copolymers prepared at conversion higher than 20 mol % become crosslinked as a result of the active participation of the furfuryl ring in the polymerization process at this temperature. © 1996 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
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  • 4
    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 kinetische Gleichung für die radikalische Polymerisation von Isopropyl-vinyl-keton in Benzol als Lösungsmittel mit AIBN als Initiator bei 60°C wurde bestimmt. Der Einfluß der Mikrostruktur auf die Photoabbaugeschwindigkeit von ataktischem und kristallinem Poly-isoproyl-vinyl-keton (PIVK) wurde auch untersucht. Die Photolyse von ataktischen und kristallinen Polymeren wurde sowohl in Lösung als auch im Festzustand durchgeführt. Die Bestrahlung verursacht Kettenspaltungen und Kettenverzweigungen oder nur Kettenspaltungen; dieses Verhalten hängt von der Packungsdichte des Polymeren ab. Es wurde festgestellt, daß die Kettenbeweglichkeit eine wichtige Rolle beim Photoabbau von PIVK spielt.
    Notes: The kinetic equation of the radical polymerization of isopropyl vinyl ketone at 60°C using benzene as solvent and AIBN as initiator was determined. The influence of the microstructure on the photodegradation rate of atactic and crystalline poly(isopropyl vinyl ketone) (PIVK) was also investigated. The photolysis of atactic and crystalline samples of PIVK was carried out in solution and in the solid state. By effect of radiation, crosslinking and chain-scission, or only chain-scission, was observed, this behaviour was depending on the aggregation state of the sample. It was proved that the chain mobility plays the main role in the photodegradation of PIVK.
    Additional Material: 6 Ill.
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  • 5
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Several kinetic aspects of the polymerization of dodecyl acrylate photoinitiated with p-nitroaniline in the presence of an aliphatic tertiary amine, either 2-(N,N-diethylamino)ethanol or 2-(N,N-dimethylamino)ethyl methacrylate, acting as coinitiator, were studied. Under low absorption conditions, the rate of polymerization was found to be proportional to the square-root of the incident light intensity, the initiator and the coinitiator concentrations. The polymerization behaviour was analyzed also under aerobic conditions. Under identical irradiation conditions, both initiation and polymerization processes present higher rates and quantum yields than those obtained with conventional aromatic ketone photoinitiators.
    Additional Material: 4 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 93 (1981), S. 159-173 
    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 Oxydation von neuen durch anionische Copolymerization aus Acrolein hergestellten Vinylacetalpolymeren wird beschrieben. 3,3-Diethoxypropen wurde als Modell verwendet und die Abbauprodukte seiner Oxydation identifiziert. Es wurde festgestellt, daß die Oxidation der Modellsubstanz zu den gleichen Abbauprodukten führt. Die Geschwindigkeit des Sauerstoffverbrauchs wurde bei allen Reaktionen volumetrisch bestimmt.Ein Mechanismus für die Oxidationsreaktion gemäß den isolierten Abbauprodukten wird vorgeschlagen.
    Notes: A study on the oxidation of new vinyl-acetal polymers obtained by anionic copolymerization of acrolein is described. Identification studies were carried out on the oxidation products of 3,3-diethoxy-propene as model compound. The products of the oxidation of the unsaturated acetal polymers were found to be identical to the products from the oxidation of the model compound. Rates of oxygen consumption by the model compound and by the polymers were measured by a volumetric method.A mechanism has been proposed taking into account the products isolated and identified and the nature of the oxidation process.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 142 (1986), S. 123-135 
    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 wurden lineare p-dimethylaminobenzoylierte Polystyrole hergestellt. Zwei Wege sind dabei verfolgt worden: Einer durch Bildung von Polystyrollithium und der andere durch Polystyrolamidbildung. Mit dem ersten Weg, Poly-p-iodstyrol → Poly-p-lithiumstyrol und Reaktionen des Polylithiumstyrols mit Methyl-4-N,N-dimethylaminobenzoat, wurde immer ein vernetztes Polymeres erhalten, das Hydroxygruppen, und in einigen Fällen  -  in Gegenwart eines Überschusses von Methyl-4-N,N-dimethylaminobenzoat und niedrigen Temperaturen  -  auch Dimethylaminobenzoylgruppen enthielt. Der zweite Weg, Polystyrolamidbildung und nachfolgende Reaktion dieser linear funktionellen Polystyrole mit POCl3 und Dimethylanilin, führte zu einem linearen p-dimethylaminobenzoylierten Polystyrol.Ausgehend von Cumol unter Anwendung derselben Prozedur wie für Polystyrol beschrieben, wurden N-Phenyl-p-isopropylbenzamid und 4-Isopropyl-4′-N-N-dimethylaminobenzophenon als Modellverbindungen erhalten. Beide Modellverbindungen und die funktionellen Polystyrole wurden mit IR, UV, 1H-NMR und Massenspektroskopie sowie Molekulargewichtsbestimmungen charakterisiert. Aus Polystyrolamid wurden auch Polystyrolester und Polystyrolsäure erhalten.
    Notes: Linear p-dimethylaminobenzoylated polystyrenes have been synthesized. Two routes, one of them by polystyrene lithiation and the other one by polystyrene-amide formation, have been followed. With the first route, poly-p-iodostyrene → poly-p-lithio-styrene and reaction of lithiated polystyrene with methyl-4-N,N-dimethyl-aminobenzoate, a crosslinked polymer was always obtained which contained hydroxylic groups and in some cases, in the presence of an excess of methyl-4-N,N-dimethylaminobenzoate and low temperatures, dimethylaminobenzoyl groups. The second route, polystyrene-amide formation and subsequent reaction of this linear functionalized polystyrene with POCl3 and dimethyl-aniline, yielded a linear p-dimethylaminobenzoylated polystyrene. Starting with cumene and following the same procedure described for the polystyrene, the model compounds N-phenyl-p-isopropylbenzamide and 4-isopropyl-4′-N,N-dimethylaminobenzophenone were also obtained. Both model compounds and functionalized polystyrenes were characterized by IR, UV, 1H-NMR and mass spectroscopy as well as molecular weight determinations. From polystyrene-amide, polystyrene-ester and polystyrene-acid were also obtained.
    Additional Material: 1 Ill.
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  • 8
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
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  • 9
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The grafting of o- and p-benzyloxybenzaldehyde onto linear chloromethylated polystyrene is described. The resulting soluble polymeric photosensitizers and their model compounds, o- and p-(p-isopropylbenzyloxy)benzaldehyde, were tested as triplet energy donors against trans-stilbene in benzene solution. Irradiation of the ortho-compounds gives rise to a transformation which has been tentatively attributed to an intramolecular photocyclization. Stern-Volmer constants for the photostable para-compounds were determined. Results for both types of compounds show that the sensitizer efficiency diminishes when it is bound to the polymer.
    Additional Material: 4 Ill.
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