Table 5. Percentage weight gain of FRP exposed to chemical treatment.
Contact time (days)
Chemical
1
7
14
21
28
56
112
Acetic acid (glacial)
0.3
0.2
0.3
0.6
0.7
0.9
1.5
Acetone
0.2
2.5
5.0
5.5
5.6
5.6
5.6
Benzaldehyde
0.5
0.5
0.8
0.7
0.7
0.8
1.3
Benzene
0.0
0.1
0.2
0.2
0.3
0.4
0.8
Benzyl alcohol
0.4
0.3
0.5
0.3
0.4
0.4
0.5
Bromochloromethane
21.2
L
N-butylamine
0.2
0.3
1.3
L
Carbon tetrachloride
0.1
0.1
0.1
0.2
0.1
0.1
0.2
Chlorobenzene
0.7
0.8
1.5
2.1
2.8
4.5
7.8
Chloroform
6.5
L
Cyclohexanone
0.2
0.2
1.1
0.3
0.6
0.5
0.1
1,2-dichlorobenzene
0.6
0.7
0.7
0.8
0.8
1.0
1.1
1,2-dichloroethane
1.0
14.0
14.6
L
trans-1,2-dichloroethylene
7.6
11.2
L
Diethylamine
0.0
0.1
0.4
0.4
0.8
1.9
3.5
Dimethylformamide
0.3
1.1
2.3
4.4
6.2
8.7
8.3
Gasoline (93 octane, unleaded)
0.1
0.1
0.2
0.2
0.1
0.1
0.1
Hexane (85% N-hexane)
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Hydrochloric acid (25% w/v)
0.1
0.1
0.2
0.4
0.7
1.8
5.0
Kerosene (K-1)
0.1
0.2
0.2
0.2
0.2
0.2
0.2
Methyl alcohol
0.2
0.6
0.9
0.9
1.1
1.5
1.9
Methyl ethyl ketone
0.1
1.5
3.6
4.6
4.9
4.8
4.8
Methylene chloride
L
Nitrobenzene
0.7
0.9
0.8
0.7
0.7
0.8
1.0
Sodium hydroxide (25% w/v)
0.0
0.1
0.1
0.2
0.2
0.4
1.5
Tetrachloroethylene
0.1
0.2
0.3
0.2
0.3
0.4
0.5
Tetrahydrofuran
0.3
2.5
6.9
9.9
L
Toluene
0.1
0.2
0.2
0.3
0.3
0.5
0.9
Trichloroethylene
0.8
7.9
16.7
16.3
L
o-xylene
0.0
0.1
0.1
0.0
0.1
0.2
0.2
glass fiber sheets separated
L
PVC appeared to be much more readily de-
dichloroethane, trans-1,2-dichloroethylene, meth-
graded than the previous materials. By the end of
ylene chloride, tetrahydrofuran, and trichloro-
the study, ten chemicals dissolved or so softened
ethylene) delaminated it, i.e., the fiberglass sheets
PVC that the test piece could not be weighed be-
separated. This occurred within the first 24 hours
cause it disintegrated (Table 6). Four chemicals
for methylene chloride and within the first one to
had this effect within the first day. Ten other
four weeks for the other solvents. The samples
chemicals appeared to soften PVC and four of
that were delaminated more slowly had weight
those chemicals caused weight gains that ex-
gains of ~1 to 16% and showed signs of swelling
ceeded 100%. Squeezing the swollen specimens
(i.e., liquid could be squeezed out of the material)
forced out some of the liquid. Only nine of the
prior to the sheets separating. Eleven other chem-
thirty chemicals used in this study had little or no
icals (including the glacial acetic acid and the so-
effect on PVC. These chemicals were the neat
dium hydroxide solution) caused weight gains of
acid, the acid and hydroxide solutions, the two
1 to 10% (Table 5). None of these chemicals caused
alcohols, three hydrocarbons (gasoline, hexane,
any noticeable swelling or softening. Again, some
and kerosene) and carbon tetrachloride. In gen-
of the specimens showed frayed edges, although
eral, PVC is especially susceptible to degradation
this may have resulted from cutting or handling
by polar, non-hydrogen-bonded solvents.*
and not chemical exposure. As with FRE, the hy-
drochloric acid solution caused a slight loss in
weight (5%). FRP appeared to be unaffected by
hydrocarbons and the nonpolar chlorinated sol-
* Personal communication, Daniel C. Leggett, Research
Chemist, CRREL, 1994.
vents.
6
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