Testing the validity of comparisons between the rheological and the calorimetric glass transition temperatures

Digital image correlation measurement of resin chemical and thermal shrinkage after gelation

“…This value is smaller than the glass transition temperature found using DSC, which was equal to T g = 193°C. The greater value of T g found using DSC measurement, as compared to rheological method, was found and discussed by Kasapis [23] et al It was suggested that the occurrence of the glass transition region in two experiments is due to the different molecular mechanisms that result in the variation of T g with the method and can be up to 25°C difference [24]. Calorimetry measurement can …”

Thermal Transition Properties of Spaghetti Measured by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT)

“…Similar exponential rise and a constant value of 55.0°C after critical heating rate (30°C/min) was observed by Rahman et al (2007) in the case of other brand of commercial spaghetti (moisture content 9.8 kg water/100 kg spaghetti). For sugar solution, an exponential T g increment was observed from 1°C/min, reaching a constant value after 10°C/min (Maurice et al 1991), while for dates (Rahman 2004), glutenin (Cocero and Kokini 1991), and gelatin (Kasapis et al 2003), a linear increase was observed. The higher heating rate shifts the transition to higher temperature due to the formation of stiff sample; however, it may be possible that, after a critical heating rate, the formation of stiff sample remains the same.…”

Viscous flow properties and phase behaviour of oil–resin blends

“…3) has been shifted to T − T g , being T g the thermodynamic glass transition temperature of this sample. For the remaining samples, all of them containing different resin concentrations, the experimental viscosity-temperature curves have been superposed Table 6 Parameters of the WLF model for the oil-resin blends master curve WLF parameters R Average deviation (%) onto the previous one (oil sample) by shifting the experimental viscosity-temperature data to T − T gRheo , where T gRheo [20] has been obtained from non-linear fitting procedures for each sample. These so-called rheological glass transition temperatures, T gRheo , obtained from the above-mentioned fitting procedure, are shown in Fig.…”

“…Rheological tests were carried out in two controlled-stress rheometers, RS150 and Rheoscope (Haake, Germany), and a controlled-strain ARES rheometer (Rheometric Scientific, USA), using cone and plate and parallel plate geometries (20,35, 60 mm diameter, 1-2 mm gap), in a temperature range comprised between −10 and 150 • C. Viscous flow measurements were performed with a Rheostress RS150 rheometer (Haake, Germany), using serrated plate-and-plate geometries (20 and 50 mm diameter; 1 and 2 mm gap).…”