Flash dsc

A Flash DSC from Mettler-Toledo,
Switzerland, equipped with a chip-sensor (MultiSTAR UFS 1, Xensor-Integration,
The Netherlands) and a Huber intracooler TC100 was used for FSC measurements.
The purge gas was nitrogen, with a flow rate of 30 mL/min. A tiny
particle with a sample mass of about 50–100 ng was placed on
the FSC sensor. A good and stable thermal contact between the sample
and the sensor was obtained after several melting-crystallization
cycles. In nonisothermal measurements, cooling rates were varied between
10 and 5000 K/s, and an optimum rate of 1000 K/s was applied for subsequent
heating. Furthermore, isothermal crystallization of PA12 in the temperature
range between 40 and 140 °C was investigated. The mass of FSC
samples was estimated by the absolute, measured heat capacity difference
at the glass transition temperature T_g of a fully amorphous sample, with the corresponding mass-normalized
values available in the literature.^{35 (link),36 (link)}

The fractions of starch particles with an average volume moment diameter D [3 (link),4 (link)] equal to 39.1 and 61.7 μm were separated from the native potato starch (SN) by measuring the volume diameter (Malvern laser particle size analyzer). Larger starch particles were acetylated with acetic anhydride in the amount of 13 cm³ /100 g of starch. After drying the acetylated starch, an initial gelatinization temperature of 49.17 °C was determined by differential scanning calorimeter Flash DSC (Mettler Toledo, Poland). The acetylated starch has been stirred for 24 h at 48 °C. It was then washed three times with five-liter portions of distilled water and separated from the slurry using the Contifuge Stratos (Heraeus, Germany) flow centrifuge. The obtained starch was dried for 24 h in an air dryer at 30 °C.