able to find a manufacturer that made FEP well
polyester resin. Its manufacturer claims that this
casings but did find one that made "pipe for sam-
product is resistant to corrosion but makes no
pling groundwater." When we tried to purchase
claims about its resistance to organic solvents. Since
the ABS well casing, we found that these manu-
the manufacturer did not specify which particular
facturers had gone out of business so we pur-
polyester was used in its product, we cannot dis-
chased waste and vent pipe. Test specimens mea-
cuss its chemical resistance except in generic terms.
suring approximately 1 cm2 were cut from each
According to Sax and Lewis (1987), polyesters are
resistant to corrosive chemicals and solvents. How-
pipe material. Special care was taken to eliminate
ever, Fuchs (1989) listed at least one organic com-
contamination from grease or oil during the cut-
pound that was a good solvent for each of the poly-
ting process. We noted that the cutting process
esters he listed.
fractured some of the specimen edges of the two
Thus, among ABS, FEP and FRE, FEP appears
fiberglass materials and were careful not to use
to be the most resistant polymer to degradation
any specimens with fractured edges. All the test
while ABS is the least resistant.
pieces were placed in 2% solutions of detergent
(Liquinox) and deionized water and stirred for
five minutes, then rinsed repeatedly with de-
ionized water until there was no evidence of
MATERIALS AND METHODS
sudsing. The pieces were drained and rinsed
Six types of 5-cm- (2-in.-) diameter well casing
with several additional volumes of deionized wa-
or pipe were used in this study: PVC, PTFE, FEP,
ter, drained, and then left on paper towels to air
ABS, FRE, and FRP. For PVC, PTFE, FRP, and
dry.
Each test specimen was weighed to 0.0001
FRE, we used well casings manufactured specifi-
cally for groundwater monitoring. We were un-
and placed in a 22-mL borosilicate glass vial.
Table 2. Percentage weight gain of PTFE exposed to chemical treatment.
Contact time (days)
Chemical
1
7
14
21
28
56
112
Acetic acid (glacial)
0.0
0.1
0.2
0.2
0.2
0.3
0.4
Acetone
0.0
0.1
0.1
0.1
0.2
0.2
0.3
Benzaldehyde
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Benzene
0.0
0.1
0.1
0.2
0.2
0.2
0.4
Benzyl alcohol
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Bromochloromethane
0.0
0.2
0.3
0.4
0.4
0.6
0.7
N-butylamine
0.0
0.0
0.1
0.1
0.1
0.1
0.2
Carbon tetrachloride
0.0
0.1
0.2
0.2
0.3
0.4
0.6
Chlorobenzene
0.0
0.1
0.0
0.1
0.1
0.2
0.3
Chloroform
0.1
0.3
0.4
0.5
0.6
0.8
1.0
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
0.2
1,2-dichloroethane
0.0
0.1
0.3
0.2
0.2
0.3
0.4
trans-1,2-dichloroethylene
0.3
0.8
1.1
1.2
1.3
1.4
1.4
Diethylamine
0.0
0.1
0.1
0.1
0.2
0.3
0.5
Dimethylformamide
0.0
0.0
0.0
0.0
0.1
0.0
0.0
Gasoline (93 octane, unleaded)
0.0
0.1
0.1
0.1
0.1
0.2
0.3
Hexane (85% N-hexane)
0.0
0.1
0.2
0.2
0.2
0.3
0.4
Hydrochloric acid (25% w/v)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Kerosene (K-1)
0.0
0.0
0.0
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
0.2
0.3
Methylene chloride
0.1
0.4
0.5
0.6
0.7
0.9
0.9
Nitrobenzene
0.1
0.1
0.1
0.0
0.1
0.1
0.1
Sodium hydroxide (25% w/v)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Tetrachloroethylene
0.0
0.2
0.2
0.4
0.4
0.6
0.9
Tetrahydrofuran
0.0
0.1
0.1
0.1
0.2
0.2
0.3
Toluene
0.0
0.0
0.1
0.1
0.1
0.2
0.2
Trichloroethylene
0.1
0.4
0.5
0.7
0.8
1.0
1.3
o-xylene
0.0
0.0
0.0
0.0
0.0
0.1
0.1
3
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