C25A/EHBT (2 wt%) is given. EHBT and 1 g of C25A were dry-mixed and meltblended at 190
C, which is within the nematic region of the polymer, for 30 min using a
mechanical mixer. The synthetic route for EHBT nanocomposite is shown in Scheme 2.
To identify chemical reactions such as transesterification and thermal degradation at
the processing temperature, the 4 wt% C25A/TLCP hybrid was annealed at 190
C.
Fig. 1 Optical micrographs
of EHBT taken at (a) 202
C
and (b) 215
C (Â250)
Table 1 General properties of EHBT hybrids with various organoclay contents
C25A
wt%
I.V.
a
T g
C
T m
C
T i
C
T D
ib
C
wt R
600c
%
LC phase
0 (pure EHBT)
0.64
92
143
225
330
37
Nematic
2
0.72
95
150
226
352
42
Nematic
4
0.68
98
150
225
352
44
Nematic
6
0.78
98
149
225
353
47
Nematic
a Inherent viscosities were measured at 30
C using 0.2 g/100 mL solutions in a phenol/1,1,2,2tetrachloroethane (w/w = 50/50) mixture
b
Initial weight reduction onset temperature
c Weight percent of residue at 600
C
21 Characterizations of Nanocomposites of Liquid Crystalline Polymers
583