Thermogravimetric analysis (TGA) tests were performed with a TGA/SDTA 851 Mettler Toledo thermal analyzer (Schwarzenbach, Switzerland). Approximately 5 mg samples were heated from 30 to 700 C at 10 C min1 under nitrogen (flow rate 50 mL min1). Differential scanning calorimetry (DSC) tests were used to determine glass transition temperatures (Tg) of all materials using a TA DSC Q-2000 instrument (New Castle, DE, USA) under nitrogen atmosphere (flow rate 50 mL min1). 3 mg samples were heated from 30 to 200 C at 10C min1 (3 min hold), then cooled at 10 C min1 to 30 C (3 min hold) and further heating to 200 C at 10 C min1.