Abstract

The creep and recovery of 5% carboxyl-terminated butadiene acrylonitrile (CTBN) modified epoxy shape memory
polymers (SMP) was studied. The results were compared with those for the unmodified epoxy SMP. The glass
transition temperatures (Tg) were determined using Advanced Rheometric Expansion System (ARES). The creep
behavior of the unmodified epoxy and 5wt.% CTBN modified epoxy SMP were studied through short-term tensile
creep test. These tests were carried out at different temperatures ranging from glassy, viscoelastic, and rubbery
regimes and different loading conditions. It was observed that Tg is slightly reduced by the addition of CTBN in
the SMP. For both the SMPs, the creep strain increases with increasing temperature and shows a maximum in
the vicinity of the Tg. Furthermore, creep strain increases with increasing load in the glassy and rubbery regimes.
A mutual comparison revealed that the creep strain was higher for unmodified epoxy SMP than that of 5% CTBN
modified epoxy SMP at all the temperatures considered. A higher percentage creep recovery was noticed in the
case of the CTBN modified epoxy SMP as compared to the unmodified epoxy SMP.