Table 3. Percentage weight gain of FEP exposed to chemical treatment.
Contact time (days)
Chemical
1
7
14
21
28
56
112
Acetic acid (glacial)
0.0
0.1
0.1
0.1
0.2
0.2
0.3
Acetone
0.0
0.1
0.1
0.1
0.2
0.2
0.2
Benzaldehyde
0.0
0.0
0.0
0.1
0.1
0.0
0.0
Benzene
0.1
0.1
0.1
0.2
0.1
0.2
0.3
Benzyl alcohol
0.0
0.0
0.0
0.0
0.0
0.1
0.0
Bromochloromethane
0.0
0.1
0.1
0.3
0.3
0.4
0.6
N-butylamine
0.0
0.0
0.1
0.1
0.1
0.1
0.1
Carbon tetrachloride
0.0
0.1
0.1
0.2
0.2
0.4
0.4
Chlorobenzene
0.0
0.1
0.1
0.1
0.1
0.2
0.3
Chloroform
0.1
0.2
0.3
0.4
0.5
0.6
0.8
Cyclohexanone
0.0
0.0
0.0
0.0
0.0
0.0
0.0
1,2-dichlorobenzene
0.0
0.1
0.1
0.1
0.1
0.1
0.1
1,2-dichloroethane
0.0
0.1
0.2
0.1
0.2
0.3
0.3
trans-1,2-dichloroethylene
0.3
0.7
0.9
1.0
1.1
1.2
1.2
Diethylamine
0.0
0.0
0.0
0.0
0.1
0.2
0.3
Dimethylformamide
0.0
0.1
0.1
0.0
0.1
0.0
0.1
Gasoline (93 octane, unleaded)
0.0
0.1
0.1
0.1
0.1
0.1
0.2
Hexane (85% N-hexane)
0.0
0.1
0.1
0.1
0.1
0.2
0.2
Hydrochloric acid (25% w/v)
0.0
0.0
0.0
0.0
0.1
0.1
0.0
Kerosene (K-1)
0.1
0.1
0.1
0.0
0.0
0.0
0.0
Methyl alcohol
0.0
0.0
0.1
0.0
0.0
0.0
0.0
Methyl ethyl ketone
0.0
0.1
0.1
0.1
0.1
0.1
0.2
Methylene chloride
0.1
0.4
0.4
0.5
0.5
0.7
0.8
Nitrobenzene
0.1
0.0
0.1
0.0
0.1
0.0
0.0
Sodium hydroxide (25% w/v)
0.0
0.0
0.0
0.0
0.0
0.0
0.1
Tetrachloroethylene
0.0
0.1
0.2
0.2
0.3
0.4
0.6
Tetrahydrofuran
0.0
0.0
0.1
0.1
0.1
0.1
0.3
Toluene
0.0
0.1
0.1
0.1
0.1
0.2
0.2
Trichloroethylene
0.2
0.4
0.3
0.5
0.6
0.8
1.1
o-xylene
0.0
0.0
0.1
0.0
0.0
0.0
0.1
mined by seeing if the specimen could be easily
Twenty-eight neat organic compounds (including
indented with the forceps using an untreated
one acid), and 25% solutions of hydrochloric acid
piece of material as a reference. After weighing,
and sodium hydroxide (Table 1) were used in this
the specimen was returned to its vial and the vial
study. Twenty-seven neat organic solvents were
was recapped. Test samples were stored at room
tested, including six hydrocarbons (aliphatic and
temperature.
aromatic), ten chlorinated solvents (aliphatic and
aromatic), seven oxygen-containing compounds
(that were either a ketone, alcohol, aldehyde, or
ether), and four nitrogen-containing compounds.
RESULTS AND DISCUSSION
Most of the test compounds were EPA priority
Tables 27 show the percentage weight gains
pollutants. Five mL of the test chemical were
for the six materials and any other observations
added to a vial and the vial was sealed with a
relative to physical degradation (swelling, soften-
Teflon-lined, plastic cap. There were no replicate
ing, decrease in strength, deterioration, and dis-
samples in this study. There were seven sampling
solution).
times: 1, 7, 14, 21, 28, 56, and 112 days. On each
Although PTFE and FEP are generally recog-
sampling day, each test coupon was removed
nized as being inert to degradation by chemicals,
from the vial using stainless steel forceps, blotted
by the end of the study they did show slight
with a paper towel and allowed to air dry for
approximately one minute before weighing (to
weight gains (~1%) when exposed to five organic
chemicals (chloroform, trans-1,2-dichloroethylene,
0.0001). Weight gain or loss was used as one mea-
methylene chloride, tetrachloroethylene, and tri-
sure of physical change. Softening was deter-
4
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