Influence of soft segments on thermo-mechanical behaviour of novel epoxy based shape memory polymers.

Epoxy based Shape Memory Polymers (SMEPs) have been formulated by reacting an aerospace grade aromatic epoxy resin with aliphatic amines. TETA (triethylenetetramine) series and TTD (trioxatridecanediamine) series SMEPs with varying soft segment contents and with glass transition temperatures (Tgs) ranging from 103-51°C have been obtained. The viscoelastic behaviour of SMEPs has been investigated using an Advanced Rheometric Expansion System (ARES). For the thermomechanical tests, the respective Tg of each SMEP has been fixed as the deformation as well as recovery temperature (shape switching temperature). Further, the effect of soft segments on thermo-mechanical shape memory behaviour of the SMEPs has been evaluated. The results reveal that TTD series SMEP with maximum soft-segment content exhibit a narrow viscoelastic region, complete shape recovery and very good shape memory behaviour. Thus based on specific applications the soft segment content may be varied suitably