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ANP PROJECT PROGRESS REPORT
which the infrared spectrometer is used, is presented
here.
The infrared spectra of polystyrene, polyethylene,
polybutadiene, GR-S, natural rubber, deproteinized
rubber, polyvinyl chloride, and Teflon have been
measured before and after irradiation. The con-
ditions of irradiation of these materials and some
others which were not studied so thoroughly after
irradiation are given in Table 4.2.4.
The polymer films were cemented on a 2.9 x 1.1
cm rectangular aluminum wire frame, evacuated
for 2 to 5 hr, and then measured to provide a
preirradiation spectrum. The films to be irradiated
in vacuum were evacuated for three to five days
at 0.2 p and sealed in vacuum in pyrex or quartz
tubes prior to irradiation. These sample tubes
Polymer
Polystyreneu 11
Polyalphamethyl styreneu 0.39, 6.9
PolyethyleneC 0.39, 3.9
Pol ybutad i one e
GR-s e 0.72, 6.5
Natural (Hevea) rubbere
Extracted Heveae
Polyvinyl chloridee 0.39, 0.72, 3.9
Polymethyl methacrylateC 0.39, 6.9
Teflong 0.72
Mylarg 0.39, 6.9
Nylong resin No. 63 0.72
~~
TABLE 4.2.4. IRRADIATION DOSAGES OF POLYMERS
were packed with aluminum foil in aluminum cans
for irradiation. The polymers were irradiated in
one or more of the following facilities: (1) a Cod'
gamma-ray source, (2) water-cooled hole No. 19
in the ORNL Graphite Reactor, and (3) lattice
position C-46 in the LITR. The maximum permis-
sible dosage was limited by the formation of open
slits in some polymer films (caused by shrinkage
and loss in film strength). It was found that the
dosage on polystyrene, polyvinyl chloride, mylar,
and polymethyl methacrylate could be increased
by irradiating ynmounted films.
The discovery that postirradiation oxidation had
occurred in irradiated polymers during exposure to
air necessitated opening the evacuated sample
tubes in a helium atmosphere. A glove box that
Irradiation Exposure (X 10' rads)
co60 Gamma, *106 r/lr Graphite Reactor, LITR, Average Sample
Y O 6 r/hr, Y O 8 r/hr, Thickness
In Oxygen In Vacuum in Vacuum
in Vacuum (in.)
2.3, 11
6.6b
1.2, 2.3, 6.2
3.8, 6.1, 8.9
3.8, 6.1, 8.9
1.4, 8.9
1.4, 8.9
3.9, 5.2, 8.9
6.5
1.5, 16, 23, 31, 35
7.0
3.4
4.0,c 14, 18
3.8, 13, 20
4.8,' 16
16, 22
12, 40b
2.0, 6.5
3.8, 6.1 16,22
2.3, 6.2 16, 17
1.4, 6.1 22
%upplied by Dow Chemical Company.
bSample crumbled; measurement after irradiation impossible.
CCommerciaI film.
9
dAlso 0.008 and 0.030 in. exposed to 0.12 X 10 rads.
eSupplied by B. F. Goodrich Co.
'Tube cracked during irradiation.
gSupplied by E. 1. du Pont de Nemours & Co., Inc.
250
1000, 1000, 1500
0.0018
0.002
0.0012d
0.003
0.002
0.004
0.004
0.002
0.0004
0.0006
0.00025
0.0015
v*
t
- -4
hps