부산대학교 도서관

The compatibility of plastic materials used in gasoline storage and dispensing applications was determined for test fuels representing neat gasoline (Fuel C), and blends containing 25% ethanol (CE25a), 16% isobutanol (CiBu16a), and 24% isobutanol (CiBu24a). A solubility analysis was also performed and compared to the volume swell results obtained from the test fuel exposures. The plastic specimens were exposed to each test fuel for16 weeks at 60°C. After measuring the wetted volume and hardness, the specimens were dried for 65 hours at 60°C and then remeasured for volume and hardness. Dynamic mechanical analysis (DMA), which measures the storage modulus as a function of temperature, was also performed on the dried specimens to determine the temperature associated with the onset of the glass-to-rubber transition (T g ).
For many of the plastic materials, the solubility analysis was able to predict the relative volume swell for each test fuel. Those plastic materials commonly used as permeation barriers exhibited the least amount of volume and hardness change (g was not measurably affected by the test fuel exposures. However, polyethylene terephthalate (PET) and the nylons were notable exceptions. The T g for PET was reduced by 30°C with CE25a, while the reductions observed for nylon depended on both nylon grade and oxygenate type.