Photodegradation of Nylon-6

Abstract

The photodegradation of unprotected bright nylon-6 fiber by exposure to daylight and in the fadeometer has been studied. The degradation has been found to be caused by random scission of the polymer chain. Although the degrada tion produces appreciable changes in the tensile strength and viscosity average molecular weight of the nylon-6 fiber, the polymer chain itself is not attacked appreciably as substantiated by infrared measurements. A possible mechanism for the photodegradative breakdown of nylon-6 fiber so far as the formation of nonvolatile water-soluble products is concerned is postulated and substantiated by identifying the degradative products obtained. The efficacy of a selected uv absorber in reducing the photodegradation of nylon-6 fiber has also been studied.

Keywords

Bright nylon-6 fiber (polyamide)protected unprotected uv absorber (2 2'-dihydroxy-4 4'-dimethoxy benzophenone). Photodegradation fadeometer temperate region tropical atmosphere controlled conditions of exposure irradiation. Mechanism of degradation random scission of the polymer chain pyrolysis peptide group pyrrole. Tensile strength viscosity m-cresol intrinsic viscosity Mark-Houwink's equation molecular weight water solubles pH Ehrlich reac tion uv spectra ir spectra.

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