Unetched POP films

SURFACE COMPOSITION OF PLASMA-ETCHED AND UNETCHED POP FILMS BEFORE AND AFTER HEAT TREATMENT... 

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... 

Infrared Spectra. Since the transmission IR spectra of the etched and unetched films were Identical, as were also the ATR spectra, and were essentially the same as that for a 2.5-um POP film presented elsewhere (, ), there was no need to show them here. 

Figure 2. Arrhenius plots for thermally induced blackening in etched ( 3.8 jxm, O) and unetched 7.5 jxm. A) POP films...

ESR Results. ESR spectra were observed in both etched and unetched samples of POP film. Within experimental error, these... 

Figure 5. ESC A spectar of POP film (a) unetched (b) oxygen plasma-etched. Solid lines measured peaks dashed lines represent deconvoluted peaks.

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