Specific volume (
v) versus temperature (
T) curves of epoxy resin cured with non-stoichiometric amounts of diethylene triamine (DETA) were studied. Experimental results are as follows : the
v-
T curves showed anomalous behavior (Shibayama, M. Kodama : Chem. Highpolymer, 20 [222], 587 (1963)). Furthermore, there were some differences between the behaviors in the region (1) where the amount of curing agent is poor and in the region (2) where it is rich. In the region (1), the specific volume at below
Tg increased orderly with increase of DETA contents, but above
Tg, it decreased orderly with increase of DETA contents. In the region (2), the specific volume at both above and below
Tg, increased orderly with increase of DETA contents. These behaviors are explained from the viewpoint of the free volume and the occupied volume of the resin.
View full abstract