Chemistry Reference
In-Depth Information
length was 40 mm. The operation tempera-
ture was fixed at 190
8
C, with experimental
loads of 20, 30, 40, 50, 60 and 70 kgf/cm
2
.
More detailed information cand be found in
elsewhere.
[12]
where W
s
, W
n
, and W
p
represents the total
weight of polymer and nickel net after
being extracted, the weight of nickel net,
and the weight of polymer, respectively.
LDPE film specimens were cast into thin
films of about 0.1 mm thickness by dropping
a dilute solution of ca. 5 wt% concentration
in xylene onto clean glass slides and
evaporating the solvent. The films were
further dried under vacuum for a few days
before use. The film specimens were care-
fully peeled from each glass slide just before
measuring the contact angle on the glass
side of the films.
The contact angles of double-distilled
water on the control LDPE and grafted
LDPE films were measured at ambient
temperature. Liquid droplet was gently
placed on the specimen. The height (h)
and the base (
Results and Discussion
FTIR Spectroscopy Analysis of the
Grafted LDPE
The FTIR spectra of LDPE, LDPE-
g
-AA,
and LDPE-g-(AA-St)
are
shown
in
Figure 1. In the cases of LDPE-
-AA and
LDPE-g-(AA-St), the new absorption band
at 1709 cm
1
was observed, which can be
assigned to the absorption of the carbonyl
groups (-C
ΒΌ
O) of AA. This new peak
confirmed that the AA monomer was
grafted onto the LDPE chain. The absorp-
tion bands at 1369 cm
1
and 1467 cm
1
,
were also observed, which can be attributed
to scissor vibrations of methyl (-CH
3
) and
methylene (-CH
2
) groups. The absorption
band at 719 cm
1
corresponds to the swing
vibration of methylene groups. In the case
of LDPE-
g
) of the droplet were
measured from the photograph and geo-
metric considerations. Each contact angle
was the average of at least eight measure-
ments.
The rheological behavior of LDPE and
LDPE-
w
-(AA-St) was investigated with an
XLY-II flow tester (capillary rheometer)
(Jinlin University Science and Educational
Instrument Plant, Changchun, China). The
fixed-temperature method was used. The
nozzle diameter was 1 mm, and the nozzle
g
-(AA-St), the characteristic
absorption band of benzene ring groups
at 700 cm
1
overlapped that of 719 cm
1
.
The intensity of the carbonyl absorption
band at 1709 cm
1
g
for LDPE-g-(AA-St)
Figure 1.
FTIR spectra of LDPE, LDPE-
g
-AA and LDPE-
g
-(AA-St).
