Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Digitale Medien  (34)
Datenquelle
Materialart
  • Digitale Medien  (34)
Erscheinungszeitraum
Schlagwörter
  • 11
    Digitale Medien
    Digitale Medien
    Photochemical reactions in a commerical poly(ether sulfone) (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 1129-1135 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: A commercial poly(ether sulfone) has been examined by electronic spectroscopy, continuous photolysis, and laser flash techniques. The spectroscopic experiments indicate that the chromophoric species primarily responsible for light absorption in the region 290-350 nm is the diphenyl sulfone unit. The laser flash experiments give direct evidence of bond scission at the ether linkage on the polymer backbone.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1977.070210425
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 12
    Digitale Medien
    Digitale Medien
    Photostabilizing effect of nickel(II) chelates in polymers. III. Effect of in situ stabilizer synthesis in polypropylene (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 611-614 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1978.070220302
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 13
    Digitale Medien
    Digitale Medien
    Photo-oxidation of commercial polyethylene containing titanium dioxide (rutile)/ antioxidant systems (1977)
    Springer
    Journal of materials science 12 (1977), S. 1320-1324 
    Details
    ISSN: 1573-4803
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The weathering performance of various grades of untreated (or uncoated) and treated (or coated) rutile pigments in commercial polyethylene in the absence and presence of primary and secondary antioxidants is examined. Using carbonyl index as a monitor of the rate of photo-oxidation, untreated rutile sensitizes the photo-oxidation of polyethylene, whereas the treated grades act as photostabilisers. The photosensitizing effect of untreated rutile is markedly inhibited by a synergistic combination of a hindered phenol (Topanol CA) and a sulphur containing antioxidant (DLTDP). Further, the order of weathering stability of the treated rutile pigments in the absence of any antioxidant in the polymer is altered significantly when an antioxidant system is present. The imporance of pigment/antioxidant interactions is discussed. The photo-oxidation of polyethylene containing the treated rutile pigments is also significantly improved by the presence of a primary antioxidant or a primary/secondary antioxidant system compared with a secondary antioxidant alone. These results indicate that peroxides play only a minor role in the photo-oxidation of TiO2 (rutile) pigmented polyethylene.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00540845
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 14
    Digitale Medien
    Digitale Medien
    Mechanism of photostabilization of polypropylene by nickel oxime chelates (1968)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 12 (1968), S. 1825-1833 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Recent work has shown that certain nickel oxime chelates act as effective light stabilizers for polypropylene. The mechanism of their protective action was examined by spectrophosphorimetry and flash photolysis. Examination of the phosphorescence from the commercial polymer shows that it is due to aldehydic carbonyl groups. From flash photolysis observations of the triplet quenching action of a range of nickel chelates it is suggested that stabilization by the oxime chelates is achieved by a mechanism of efficient energy transfer from the photoreactive carbonyl group to the chelate, where the energy is harmlessly dissipated. The efficiency of this quenching action is primarily dependent on the spatial configuration of the ligand around the central metal atom in the chelate.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1968.070120803
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 15
    Digitale Medien
    Digitale Medien
    Mechanism of the benzophenone-sensitized photodegradation of polypropylene (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 3179-3179 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1974.070181024
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 16
    Digitale Medien
    Digitale Medien
    Mechanism of the benzophenone-sensitized photodegradation of polypropylene (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 17 (1973), S. 3503-3508 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The photodegradation of polypropylene sensitized by benzophenone has been studied under accelerated light-aging conditions using a Xenotest 150. Degradation of the polymer and consumption of the benzophenone was monitored by infrared spectroscopy. The results indicate that hydrogen stom abstraction from the polymer, by photo-excited benzophenone, is the major primary process in the mechanism of sensitized photodegradation.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1973.070171121
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 17
    Digitale Medien
    Digitale Medien
    Photostabilizing effect of Ni(II) chelates in polymers. II. Effect of diamagnetic chelates on polypropylene phosphorescence (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 2805-2807 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Examination of the phosphorescence emission form polypropylene shows the lifetime of the emission to be unaffected by a hydroxybenzophenone light stabilizer but significantly shorted by a diamagnetic Ni(II) chelate stabilizer.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1974.070180921
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 18
    Digitale Medien
    Digitale Medien
    Origin and role of the luminescent species in the photo-oxidation of commercial polypropylene (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 2261-2267 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The fluorescence and phosphorescence excitation and emission spectra of commercial polypropylene have been examined using a fully compensated spectrofluorometer. This has made possible the comparison of the excitation spectra of the polymer with model chromophores of those believed to be present in the polymer. The fluorescence emission is primarily associated with the presence of enone, and the phosphorescence with dienone chromophoric units. The behavior of the luminescent enones and dienones during irradiation under sunlight-simulated conditions has also been examined. Possible mechanisms for the participation of these chromophoric units in the photo-oxidation of polypropylene are discussed.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1977.070210823
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 19
    Digitale Medien
    Digitale Medien
    Evidence for the reduction of quinones added during thermal processing of polypropylene and the resultant effect on polymer light stability (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 1451-1457 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The thermal and photochemical oxidation of anthraquinone- and p-benzoquinone-doped polypropylene has been studied by absorption, luminescence, and infrared spectroscopy. Prior to irradiation, fluorescence and phosphorescence measurements showed that some of the anthraquinone and most of the p-benzoquinone had been converted into their corresponding hydroquinones during processing. The p-benzoquinone, unlike anthraquinone, also imparted a blue coloration to the polymer before irradiation, which is associated with the formation of a quinhydrone complex (or complexes). These results indicate that the quinones are thermally reduced to their corresponding hydroquinones during processing by a mechanism of hydrogen atom abstraction from the polymer substrate. On photo-oxidation, whereas anthraquinone acted as a photosensitizer, p-benzoquinone acted as a photostabilizer.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1978.070220601
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 20
    Digitale Medien
    Digitale Medien
    Photostabilization of commercial polypropylene by a hindered amine stabilizer (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 3277-3282 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The photostabilization of commercial polypropylene by a hindered amine stabilizer is examined by luminescence and ESR spectroscopy. The presence of the amine stabilizer inhibits the photolysis of the α,β unsaturated carbonyl impurity groups present in the polymer. Examination by ESR, of the stabilized polymer before and after irradiation shows the development of a highly stabilized free radical indicating that the stabilizer can act as an ultraviolet stable antioxidant. Possible mechanisms whereby the hindered amine inhibits the photolysis of the α,β unsaturated carbonyl groups are discussed.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1978.070221121
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...