Viscosity Determination

The rheology (viscosity) of the solution was determined using a Viscotech 3000 viscometer (Viscotech Hispania, SL, El Vendrell-España, Spain) according to the Brookfield method. A 20 mL sample was analyzed at room temperature (22 ± 0.5 ◦C) in an appropriate container providing convenient spindle-to-wall distance.

#### Fourier-Transform Infrared Spectroscopy (FTIR)

Fourier-transform infrared spectra analysis of WTPS was performed using a Spectrum One ATR-FTIR spectrometer (Perkin Elmer, Waltham, MA, USA). Scans were performed between the infrared regions at 4000–400 cm<sup>−</sup>1, with an average of 64 scans.

#### Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR)

Proton nuclear magnetic resonance spectroscopy of WTPS was performed using an Agilent Technologies DD2 spectrometer (Agilent Technologies, Santa Clara, CA, USA). The WTPS samples were dissolved in D2O with trifluoroacetic acid (TFA) and deuterated chloroform (CDCl3) for the purpose of analysis.

#### Differential Scanning Calorimetry (DSC)

Differential scanning calorimetry of purified WTPS was conducted with a differential scanning calorimeter (TA Instruments Q20, New Castle, DE, USA) within the range of

−60 to 150 ◦C. A small amount of sample (2–5 mg) was placed into a DSC pan and analyzed with a heat rate of 10 ◦C/min.
