DSC was conducted using a DSC Q2000 (TA Instruments, Newcastle, DE, USA). Samples of about 10 mg were prepared in sealed aluminium pans and heated from +5 °C to +200 °C and subsequently cooled to -50 °C at a linear rate of 10 °C min -1 in a nitrogen atmosphere. This cycle was repeated three times, with a final cooling to room temperature. The glass transition temperature (Tg) was obtained from the inflection point of the second and third heating cycle and the melt temperature (Tm), if applicable, as the peak maximum of the endothermic curve in the first heating. The data were evaluated using Origin software.