Tga dsc 2

TGA and DSC measurements were performed simultaneously by using a TGA/DSC2 (Mettler Toledo, Greifensee, Switzerland) according to a previous study [37 (link)]. The sample synthesized by chemoenzymatic polymerization (5–7 mg) was weighed and sealed in an aluminum pan. The lid of the aluminum pan had a pinhole to prevent the pan from bursting because of an increase in the internal pressure during the heating process. The product was heated at 10 °C/min from 30 to 400 °C under a nitrogen atmosphere in triplicate. The device was calibrated with an empty cell to form a baseline and with indium to characterize the heat flow and temperature of the system.

TGA measurements were performed using TGA/DSC 2 Mettler-Toledo, Giessen, Germany). The analysis was performed under argon flow (20 mL/min) in the temperature range 30 to 800 °C at a heating rate of 5 K min⁻¹.

The polysaccharide was accurately quantified (10 mg) and placed in a crucible. The temperature range was set to 30–650°C with a linear heating rate of 5°C/min. The flow rate of N₂ in the sample chamber was 20 ml/min. The polysaccharide samples were analyzed by thermogravimetry (TG) and differential thermogravimetry (DTG) under the above conditions (TGA/DSC2, Mettler Toledo, CHE).

The FTIR spectra of poloxamer188, ε-CL, and PCL were obtained from an FTS-135 (BIO-RAD, USA) spectrometer, scanning from 4,000 to 500 cm⁻¹. KBr pellets were prepared under a hydraulic pressure of 400.0 kg at the KBr and specimen ratio of 10:1 (m/m). Meanwhile, Raman spectra were also used to study the structure of final copolymers. All spectra were recorded on a Metage OPAL Portable Raman System (ProRoman L-785, EVWAVE Optronics. lnc), covering a range of 3,200–3250 cm⁻¹ at a spectral resolution of 4 cm⁻¹, and each sample was scanned for 10 times.
¹H NMR spectrum was used to analyze the structure of the obtained copolymers. ¹HNMR spectra were recorded on a Bruker 400 MH_Z nuclear magnetic resonance instrument with CDCl₃.
Mettler-Toledo TGA/DSC-2 (Switzerland) was sued to study the thermo-stability of poloxamer188 and poloxamer188-b-PCL. About 5.0 mg of samples were loaded into ceramic pans (50 μl), and their TGA curves were recorded under the atmosphere of high purity nitrogen (flow rate of 20 ml/min) heating from 25 to 500°C at the rate of 10°C/min.
The molecular weight of poloxamer188-b-PCL was measured with Waters 1515 GPC (Waters Company, USA). THF was selected as the mobile phase, and the flow rate was set as 1.0 ml/min. Polystyrene with the molecular weights of 100–500,000 were used as reference substances.

The morphology and structure of samples was characterized by SEM (FEI Quanta 450). HAADF-STEM images were recorded at 200 kV (Talos F200X). XRD data were recorded on a Rigaku MiniFlex 600 X-Ray Diffractometer. Sulfur content of the active material was determined by TGA (METTLER TOLEDO TGA/DSC 2) under N₂. In-situ synchrotron XRD (with wavelength λ = 0.6888 Å) and NEXAFS data were detected on the powder diffraction and the soft X-ray spectroscopy beamline in the Australian Synchrotron, Clayton, Victoria.

Thermal properties of TBs-10-30k were analyzed by thermogravimetry (TG) and differential scanning calorimetry (DSC) using TGA/DSC 2 and DSC 1 analyzers (METTLER TOLEDO, Zurich, Switzerland), respectively. In brief, the sample was accurately weighed and placed in the alumina crucible. For TG analysis, the sample was heated at temperatures from 30 to 800 °C under nitrogen gas stream flowed at a rate of 20 mL/min; for DSC analysis, the sample was heated from 30 to 600 °C. The heating rates of both analyses were set at 10 °C/min [24 (link)].

The investigated materials have either been tested as delivered, or, if necessary, were mixed and stirred at a temperature above their melting point for at least 30 min. The following devices have been used for DSC measurements: The Mettler Toledo DSC 823e (Nänikon, Switzerland) with FRS 5+ sensor (Mettler Toledo, Nänikon, Switzerland) and TC100 Intracooler (Huber Kältemaschinenbau AG, Küsnacht, Switzerland), the Mettler Toledo DSC 3+ (Nänikon, Switzerland) with FRS 6+ sensors (Mettler Toledo, Nänikon, Switzerland) and both TC45/100 Intracoolers (Huber Kältemaschinenbau AG, Küsnacht, Switzerland). For the TGA measurements, a TGA/DSC 2, TGA/DSC 3+ and TGA/DSC 1 from Mettler Toledo all equipped with a DTA or DSC sensor were used. Equipment is shown in Supplementary Figure S1.