Thermo-mechanical behaviour of Shape Memory Polymers, e.g., Tecoflex® by 1WE method: SEM and IR analysis

Thermomechanical cycles including programming, cooling, unloading and heating to trigger the 1WE were examined for a shape memory polymer (SMP), TecoflexA (R) (TFX EG-72D). Cycles were performed at 60 A degrees C with 65% strains and the recovery time of 10 min. Strains evolving with time were estimated during the thermomechanical treatments for the total 50 cycles using 65% strains. Recovery ratios for 65% strains were also estimated. It turns out that programming, cooling, unloading and heating to trigger the 1WE causes an increase of irreversible strain and is associated with a corresponding decrease of the intensity of the 1WE in particular during the first thermomechanical cycles. Gold coated scanning electron microscopic study using secondary electron imaging (120 times magnified) shows a very little wavy surface structure evolve during cycling up to 300% strains. IR study accurately features the chemical nature after cycling, processing and programming of TFX EG-72D.