Weight change data, significance

Carbon dioxide at high pressure can be absorbed into, swell and in some cases dissolve some polymers as evidenced by weight change data. Amorphous polymers have shown more significant sorption. 

Similar to CAB, PMMA showed extensive foam formation after treatments at both conditions. Similarly, foam formation in these sample was also more extensive when shorter decompression times are used. As evidenced in the weight change data (see Sec. 2), PMMA shows a significant COj uptake, leading to extensive foam formation during PVC, POM, ABS decompression. The dramatic decrease in (see Sec. 3) also substantiates the extensive dissolution of CO2 in this polymer. 

Figure 6-11. Specimen weight change during 1-h cycles at 1150 °C for a variety of Ni-Al alloys (at.%). Weight losses indicate scale spallation. Near stoichiometry there is very little effect on spallation for undoped alloys. Alloys of 45 at.% Al or below formed more Ni-rich oxides and a larger amount of spallation was observed. Addition of Hf and Pt significantly improved scale adhesion during this test (data from Pint and Wright (1998) and Pint etal. (1998a)).

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