Tga dsc 2 star system

Thermogravimetric analysis (TGA) was performed using a Mettler Toledo TGA/DSC 2 STAR System (Mettler Toledo, Giessen, Germany) in ramp mode heated from 0 to 600 °C, with a heating rate of 10 °C/min and a flow rate of 20 mL/min of N2. The derivative TG (DTG) curve was created to describe the weight loss rate as a function of temperature [33 (link)].

TGA was performed using a TGA/DSC 2 STAR system (Mettler-Toledo, Columbus, OH, USA) on sample amounts of 5–8 mg. A program was created to run the analyses from 25 to 600 °C with a heating rate of 20 °C/min and flow rates of 65 cc/min for Ar, 20 cc/min for O₂, and 1 cc/min for CO₂. Ash weights were determined by the mass remaining at 600 °C.
Mineral weight percentages (ash weights) from TGA were fit to the Avrami equation: $$\frac{\mathrm{Y}}{{\mathrm{Y}}_{\max }}=1-\exp \left(-{\mathrm{Kt}}^{\mathrm{n}}\right)$$
using MATLAB. In this equation, Y is the mineral amount in weight percentage, Y_max is the maximum mineral amount possible, t is time, and K and n are Avrami constants [47 ]. R² values for the linearized fits for this model were 0.91 and 0.98 for OPN and pAsp specimens, respectively.

Thermal stability and transitions used a TGA/DSC 2 STAR System instrument (Mettler Toledo, Columbus, OH, USA). Heating program: from 25 °C to 900 °C; heating rate: 20 °C/min; nitrogen flow: 60 mL/min. Weight loss was shown as a temperature function from a single sample run. Heat flow was shown as a function of temperature respectively.

Powder X-ray diffraction (PXRD) data were recorded on a high-throughput Bruker D8 Advance diffractometer working on transmission mode and equipped with a focusing Göbel mirror producing CuKα radiation (λ = 1.5418 Å) and a LynxEye detector. Nitrogen porosimetry data were collected on a Micromeritics Tristar instrument at 77 K. SEM-EDX results were recorded with an FEI Magellan 400 scanning electron microscope. TGA data were collected on Mettler Toledo TGA/DSC 2, STAR System apparatus with a heating rate of 2 °C/min under the oxygen flow. Elemental analyses were performed on a Vario EL-III elemental analyzer. Solid-state NMR spectra were recorded with an Advance Bruker 500 NMR spectrometer. Circular dichroism (CD) spectra were recorded on a Chirascan™-plus CD Spectrometer (Applied Photophysics). The far ultraviolet spectra (185–260 nm) were measured at 20 °C in quartz cells of 0.4 cm optical path length. Spectra were acquired at a resolution of 1 nm, with time per points set at 0.7 s and a bandwidth of 1 nm.

The TGA were performed on a TGA/DSC 2 STAR System thermogravimetric analyzer, Mettler Toledo, USA. The samples (10 ± 0.5 mg) were placed in alumina (Al₂O₃) crucibles at a heating rate of 20 °C min⁻¹ using a nitrogen purge at a flow rate of 60 mL/min, and the analysis was done at a temperature range between 30 and 600 °C. DSC analyses were performed on a TA Instruments model Q-2000 machinewas done by sealing ~10 mg of the sample in aluminum pans and put through heating condition at a rate of 10 °C min⁻¹. The samples were subjected to heating–cooling–heating cycles. They were firstly heated from −25 to 200 °C, then were cooled from 200 to 25 °C and were again heated from 25 to 200 °C. For the evaluation of thermal properties, the results of the second heating run were used because of the elimination of the thermal history of the test specimens. The calculations are based on ΔH_m⁰ for 100% crystalline PLA being equal to 93 J/g [37 (link)]. The degree of crystallinity (X_c) of the blends could be calculated from the melting enthalpy in the secondary heating curves (ΔH_m) according to the following equation:
where ω_PLA is the mass fraction of PLA in the blends and ΔH_cc is cold crystallization enthalpy.