Etched films, photo/thermal degradation

Plasma Etching of Poly[A A -(/),/> -Oxydiphenylene) Pyromellitimide] Film and Photo/Thermal Degradation of Etched and Unetched Film... 

The desired thickness of the film for the solar sail application was 2.5 ym, but the thinnest commercially available film of this type was Du Font s Kapton O) with a thickness of <7.5 ym. Hence, a need existed to thin the latter film and to assess the photo-and thermal stability of the resulting, thinned film. This paper describes the use of a radiofrequency (RF) oxygen plasma for etching (thinning) of poly[, N-oxydiphenylene) pyromellitimide] (POP) film, and presents data on the photo/thermal degradation of etched and unetched film in vacuum. Although plasma etching has been applied to many polymers, it has scarcely been used on... 

Photo/thermal Degradation. Samples of etched ( <2.5 pm) and unetched ( X/7.5 pm) POP film were placed in quartz tubes which were continuously evacuated while being heated at temperatures >450 C in a constant temperature block, controlled to 2 C. Other film samples contained in quartz tubes evacuated to <10 Torr were exposed to a Hanovia 450-watt mercury lamp with the etched side facing the lamp. At 14 cm from the lamp, the intensity of the uv radiation incident on the films was equivalent to <5.9 times that of the Sun in the 2000-3500-A range at 1 astronomical unit, i.e., just outside the atmosphere. At that distance from the lamp, the temperature of... 

Photo/thermal Degradation. Although transmission or ATR IR spectra gave no Indication of a photo- or thermally-induced alteration In the POP microstructure, the uv-lrradlated or heated films showed a definite darkening or blackening. As may be seen from Table II, the rates for photolnduced blackening In etched and... 

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