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 mechanism of dye-sensitized photo-oxidative degradation of nylon 66 was investigated. A known phototendering dye, C.I. Acid Blue 40 (1-amino-4-(p-aminoacetanilide)-2-anthraquinone sodium sulfonate), was used for this study. Excitation and emission spectra of the dyed and undyed nylons indicated that a ground-state complex between the dye and the polyamide was formed upon dyeing. The energy level of the complex's electronic states favor triplet-triplet energy transfer from the nylon to the complex. Quenching studies show that the energy transfer occurs efficiently with a rate constant of 45.8 l. mole-1 sec-1. An additional energy transfer occurs between the excited free dye and the complex by either a singlet-triplet or a triplet-triplet mechanism. Kinetic analysis of the nylon-complex energy transfer suggests that the triplet energy of nylon migrates 24 to 33 Å along the amide chromophores in an exciton fashion until an energy trapping complex is reached. Energy is then transferred by an exchange mechanism. Photo-oxidative studies verify that the dye-nylon complex sensitizes the polyamide photo-oxidative degradation at its own expense without dye photobleaching.
Zusätzliches Material:
14 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/app.1975.070190707
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