26 Bifunctional Silicas with Immobilized Lignin
423
Table 26.3
Thermal behavior parameters and characteristics of silica/lignin composites from DSC measurements at two heating/cooling cycles in
interval
−50–350 ◦
C: temperature of water evaporation (T
ev , ◦
C) on the first heat stage and interval (T
s
− T
f ); temperature (T
endo ) and heat of endo-effects
(H, J/g) on the second heat curve; and results on hydration for selected samples for ambient (40 rh%) and very high (98 rh%) relative humidities (rh)
Sample
First heating
Second heating
Hydration, on dry basis
T
ev , ◦
C
T
s
− T
f
H
1, J g −1
(±10 J/g)
T
ev , ◦
C
T
s
− T
f
H
2 J g −1
(±5 J/g)
rh 40%
rh 98%
Lignin (sample 1)
115
40–150
199
180/250/325
50–340
175
0.08
0.84
Lignin (sample 2)
106
40–150
164
180/250/325
50–340
116
Lig-A1
99
30–150
112
244
150–300
15
0.06
0.30
Lig-A2
95
30–150
77
227
130–286
38
0.05
0.26
Lig-A3
97
30–150
123
227
60–290
90
Lig-A4
91
30–150
100
245
70–290
52
Lig-A5
99
30–150
127
200
35–325
97
Lig-A6
89
30–150
160
222
100–296
51
Lig-A7
84
30–150
82
235
130–303
58
Lig-A8
92
30–150
103
216
122–301
76
Pristine silica
100
30–150
89
–
–
–
0.07
0.60