Civil Engineering Reference
In-Depth Information
illustrates the TGA curves of carboxymethylated (c) NFC from rei ned bleached beech
pulp (RBP) (RBP-c), a mechanical disintegrated one (RBP-m) and a combination of
these two methods with various sequences including RBP-mc and RBP-cm [65]. h ey
stated that carboxymethylation led to a drop of cellulose degradation temperature from
300 to 200°C.
D i f erential scanning calorimetry (DSC) can be considered as another thermal test
method to measure the glass transition temperature (T
g
) of nanocellulose samples. In
this context, nanocellulose samples are heated from room temperature to 600°C under
nitrogen l ow with a rate of 10°C/min [138]. Figure 11.15 illustrates the DSC curve of
bleached kenaf core, unsulfated and sulphated CNC [138]. h ey found that the loss
of water shown by the i rst endothermic peak was around 32°C to 130°C for bleached
kenaf and 32°C to 140°C for unsulfated and sulfated CNC. h ey also stated that the sec-
ond endothermic peak which represents degradation temperature was 350°C, 298°C
and 200°C for bleached kenaf, unsulfated CNC and sulfated CNC, respectively. h e
authors attributed the low degradation temperature of sulfated CNC to the remaining
100
100
80
80
RBP-mc
RBP-c
RBP-cm
60
60
40
c
40
20
RBP-
RBP-m
20
b
0
a
0
100
200
300
400
500
600
100
200 300
Temperature (°C)
400
500
600
700
Temperature (°C)
(
a
)
(
b
)
Figure 11.14
TGA curves of (A) CNC from jute i ber:
(a)
untreated,
(b)
alkali-treated and
(c)
CNC
[137] (B) NFC from RBP-c, RBP-m, RBP-cm, RBP-mc [65].
10
5
0
-5
Bleached Kenaf Core
Sulfated NCC
Unsulfated NCC
-10
100
200
300
Temperature (°C)
400
500
800
Figure 11.15
DSC curve of bleached kenaf core i ber and CNC [138].
