Chemistry Reference
In-Depth Information
The thermal stability of the cured epoxies can be improved through introduction of
an aromatic imide structure by using either imide-containing epoxy or curing agents
[7-9].
Figure 1.9
illustrates the synthesis of
two rosin-derived dicarboxylic acids
which contained imide structures [10]. One of the rosin derivatives, i.e., rosin-maleic
anhydride imidodicarboxylic acid (RMID), had one terminal rosin moiety and was
prepared by reacting maleopimaric acid with
p
-aminobenzoic acid. The other rosin
derivative, i.e., dirosin-maleic anhydride imidodicarboxylic acid (D-RMID), had
two rosin terminal moieties and was obtained by one-step Diels-Alder reaction with
1,10-(methylenedi-4,1-phenylene)bismaleimide (BMI). For comparison, an imide-
diacid derived from trimellitic anhydride was also prepared. Curing of a commercial
liquid epoxy resin (DER6224) using these imide-diacids, and the tensile and thermal
properties of the cured resins were studied.
Figure 1.9
Schematic synthesis routes for rosin-derived imide-diacids. Reproduced
with permission from
X. Liu, W. Xin and J. Zhang,
Bioresource Technology,
2010,
101
, 2520.
2009, Elsevier [10]
Figure 1.10
shows the dynamic mechanical properties of epoxy resins cured by these
three imide-diacids. The resins cured with RMID and D-RMID displayed higher
