Fade-ometer

Influence of Wavelength of Radiation. Our initial indications of crosslinking were observed during exposures in an Atlas Electric Devices Co. carbon-arc Fade-ometer equipped with a Corex D filter. Later, the same behavior was found when exposures were made in an Atlas 600WRC xenon-arc Fade-ometer having Pyrex-glass filters. 

Table I Tendency of Methacrylate Polymers to Become Insoluble Samples on Aluminum Foil, Single-Carbon-Arc Fade-ometer (Corex D Filter), 62°C...

Elvacite" is a registered trademark of the duPont Company, "Acryloid", a registered trademark of the Rohm and Haas Company and "Fade-ometer", a registered trademark of the Atlas Electric Devices Company. 

Table II Check on Reciprocity Law Induction Time for Cross-linking of Elvacite 2046 Under Various Intensities of Illumination In a Xenon-Arc Fade-ometer With Pyrex-Glass Filter...

Nyqvist H. Light stability testing of tablets in the Xenotest and the Fade-ometer. Acta Pharm Suec 1984 21 245-252. 

Embrittlement vs. Fade-Ometer Exposure Hours to Embrittle- Fim Thickness,... 

The importance of the polymeric form was pointed up in Fade-ometer and sunlamp tests where polyphosphites were found to be much more effective than mono (tris) phosphites derived from the same starting hydroquinones, especially when the compounds were used in conjunction with thiodipropionate esters. The data in Table IV show a comparison between a polyphosphite and a mono (tris) phosphite derived from the same substituted hydroquinone. A commonly used hindered phenolic was also tested in place of the phenolic phosphite for comparison. The protection against embrittlement obtained with the polymeric phenolic... 

Figure 2. Carbonyl absorption of irradiated polystyrene (Fade-ometer exposure)...

Exposure Conditions. Fade-ometer (Atlas, model FDA-R) all samples were mounted and exposed according to standard procedures. 

Hindered Phenols. Because of the relationship between photooxidation and discoloration, we became interested in the effect of hindered phenols which are well-known oxidation inhibitors. A preliminary study was carried out to determine the relative effectiveness of a variety of such compounds, many of which are commercially available. The additives were incorporated into polystyrene at 0.1% concentration, and 50-mil molded plaques were exposed to a carbon-arc Fade-ometer. 

Figure 6. Inhibition of discoloration with benzophenone-antioxidant combination—Fade-ometer exposure...

Figures 6, 7, and 8 show the stabilizing efficiency of the combinations consisting of the above absorbers and the antioxidant 2,4,6-tri-fert-butyl-phenol, on Fade-ometer exposure. The total additive concentration in each polystyrene sample was 0.25%. The data show that the rate of discoloration of the polymer was inhibited to a greater extent with the ultraviolet absorber-antioxidant combinations than with the absorber alone. Only a small amount (0.075%) of the antioxidant was required for increased effectiveness of the combination.

In our stabilization studies on polystyrene, we also examined various light sources and found that in addition to the carbon-arc Fade-ometer, the xenon-arc and a recently proposed high output fluorescent lamp also... 

The Fade-ometer (Figure 13) did not show a single line relationship. However, in view of the necessity for short term exposures, the qualitative correlation obtained could be quite useful for laboratory screening and... 

It appears, therefore, that two accelerated devices may be needed an exposure unit, such as the Fade-ometer, for quick screening and relative performance studies of light-stabilized polystyrene samples, and a second unit, such as the high output fluorescent lamp, for predicting more accurately long term exposures. 

A carbon-arc Fade-ometer with emission in the region of 3000-4000 A. 

Figures 18 and 19 show that inhibition of discoloration by these additives under Fade-ometer exposure was also accompanied by inhibition of carbonyl formation.

Test according to A.A.T.C.C. Standard Test Method 16-A-1964 (Fade-Ometer, carbon arc). 

Atlas Fade-ometer and Weatherometer, Bulletin No. 1300 C, Atlas Elec-... 

Figure 22.6. Accelerated weather testing, (a) Xenon arc Fade-Ometer. (Courtesy of Atlas Electric Devices Company.) (b) Fluorescent lamp QUV accelerated weathering tester. (Courtesy of Q-Panel Company.) (c) Xenon arc Weather-Ometer. (Courtesy of Atlas Electric Devices Company.)...

Exposure of Bleached Pulp. Bleached pulp, based on 50% hardwood and 50% softwood kraft, jordaned to a Canadian standard freeness of 300-350 mL, was kindly supplied by Andrew Chase of the University of Maine. Unaged handsheets made from this pulp contained 85% a-cellulose (3) and 5% hot-1%-alkali-soluble matter (4). In the experiment illustrated in Figure 1, sheets were exposed in the Atlas 6500-W xenon-arc Fade-ometer equipped with Pyrex-glass filters the air temperature was 31 °C, and the relative humidity was 27% the black-panel temperature was 65 °C. Halfway through the reported period of... 

Figure 1. Change in 2/ DPV with time of exposure of bleached-sulfate-pulp handsheets in xenon-arc Fade-ometer.

Handsheets were exposed in the Fade-ometer for periods up to 299.0 h. 

Several years ago we began to express the results of our thermal and photochemical degradation experiments in terms of Equation 4. Figure 1 shows some of the initial data obtained, relating to exposure of test sheets in the Fade-ometer. Just as Daruwalla and Narsian (16) observed, there seems to be a break in the curve. If the first stage indeed represents weak links, about 3 such bonds per 10,000 in the original cellulosic chain (0.03 ) are apparent, a figure similar to the fraction of labile acid-sensitive links determined by Sharpies (21) and labile photochemically sensitive links reported by Daruwalla (16) when radiation at 2540 A was used. 

The fluorescent lamps were mounted 3 % in. above the samples in a room maintained at 50% rh and 21.1 °C (70 °F). Under these conditions the temperature of the handsheets reached 24 °C. In the 6500-W Fade-ometer, the air temperature was 31 °C, the relative humidity was about 27%, and the black-panel temperature was 65 °C. 

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