Chemistry Reference
In-Depth Information
the presence of ester carbonyls (d 173 ppm) from the oil triglyceride
structure. There is no signal at d 52 ppm which indicates that the C-C epoxy
bond has been converted to an ether, and confirms that the EuO has been
polymerized through ring-opening polymerization and that cross-linked
polymers were formed.
3.4.3 Thermal Stability of the Polymers
To better understand the thermal properties of the resulting polymers, TGA
was used to investigate their thermal decomposition behavior under a ni-
trogen atmosphere. Figure 3.11 shows the TGA curve of RPEuO-I (the non-
soluble fraction after extraction). It can be seen that RPEuO-I appears to be
thermally stable at temperatures below 200 1C. Two distinct temperature
regions are observed where samples experienced weight loss (220-320 1C)
and (340-437 1C). The material slowly loses about 2% of its weight at tem-
peratures between 220 and 320 1C, followed by an abrupt weight loss of 80%
between 340 and 437 1C. TGA measurements revealed a total 98% weight loss
observed at temperatures between 240 and 437 1C. For the other RPESO
samples obtained at various temperatures and initiator concentrations, their
TGA curves showed similar behavior to RPEuO-I. Some samples showed less
than 5 wt% loss around 220 1C. Table 3.5 summarizes the thermal stability
Figure 3.11 TGA thermogram of RPEuO-I, weight loss vs. temperature (under a N
2
atmosphere).
