Advantage software

The phase transformations of the NiTi alloy can be investigated by differential scanning calorimetry (DSC) analysis, in which the difference between the heat energy supplied and an inert specimen heated at the same rate is measured precisely. Three unused samples for each of the eight products were prepared for DSC analysis. The DSC analyses (Model 2920 DSC, TA Instruments, New Castle, DE, USA) were conducted over a temperature change starting at 25°C. Each instrument was heated to 100°C to obtain a heating curve and then cooled to −100°C to obtain a cooling curve. Finally, instruments were heated again to 80°C. The heating and cooling rates were 10°C/min. The heat flow of each specimen during the temperature change was recorded in diagram form, which was then analyzed by computer software (Advantage software, TA Instruments) to obtain the peak temperature points of the phase transformation and enthalpy changes associated with these processes.

DMTA of TPURs was performed in tensile mode using DMA Q800 Analyzer TA Instruments (New Castle, DE, USA). Calibration was performed as per the manufacturer’s recommendations included in Advantage Software, version 5.5.24 (TA Instruments, New Castle, DE, USA). The experiments were carried out on rectangular samples of dimensions close to 1 mm thick, 5 mm wide, and 30 mm long. Experimental conditions employed were frequency of 1 Hz and static stain 0.05% with the scanning temperature range from −100 °C to 180 °C in the air conditions and a temperature ramp of 3 °C/min. The samples were cut from the pressed sheets. The variations of storage modulus (E′), loss modulus (E″), and tangent delta (tanδ) versus temperature were determined.