Sdt q600 thermogravimetric analyzer

Digital melting point apparatus (Electro thermal- IA9100) recorded the melting points using heating rates of 1 °C min⁻¹ near the melting points. The structural composition of the synthesized compounds was determined by Perkin Elmer 16 F PC Fourier transform infrared (FT-IR) spectrometer (spectral resolution: 4 cm⁻¹, number of scans: 16), and ¹H and ¹³C NMR using DMSO-d₆ on a Bruker 400 MHz spectrometer. The elemental composition was determined on a Perkin Elmer Elemental Analyzer (Series 11 Model 2400) (Waltham, Massachusetts, USA). A TA Instruments SDT Q600 thermogravimetric analyzer was used to perform the thermogravimetric analysis (TGA) under nitrogen (N₂; flow rate of 50 mL min⁻¹) using a matched platinum/platinum–rhodium thermocouple pair, and increasing the temperature from 20−800 °C by 10 °C min⁻¹. Size exclusion chromatography (SEC) was performed using a MCX column connected with a Viscotek SEC system, and was calibrated against narrow molecular weight polyethylene glycol standards. The polymer solution was prepared in 0.05 M of LiCl and 0.05 M of phosphoric acid, and NMP was used as an eluent.

Surface morphologies of the polyester/spandex textiles before and after PPy modification were characterized using a JSM-7600 FESEM (JEOL, Tokyo, Japan). A smartphone-attached optical microscope (Wellwa, Guangdong, China) was applied to image the structural change of the PPy-coated textile under tension at micrometer scale. The surface functional groups and the thermal stability of the textile before and after PPy coating were examined with a Fourier transform infrared spectrometer (FTIR, Nicolet 6700, Thermo Electronic Corporation, Waltham, MA, USA) and a SDT-Q600 thermogravimetric analyzer (TA Instruments, New Castle, DE, USA), respectively.

The gradient coating powder with 90 μL was analyzed via DSC-TGA under an air atmosphere with an SDT~Q600 thermogravimetric analyzer (TA Instruments, New Castle, DE, USA). The heating rate was 10 °C/min, and the temperature range was 30–1000 °C. A Rikkyo TTR3 X-ray diffractometer (Tokyo, Japan) was used to analyze the phase of the coating before and after oxidation. Its maximum rated output power is 18 KW, the tube voltage is 20–60 kV, the tube current is 10–300 mA, the anode is Cu, the scanning speed is 4°/min, and the scanning range is 10°–90°. A LEO 1450 scanning electron microscope (Zeiss, Oberkochen, Germany) was used to analyze the morphology of the coating surface before and after oxidation. The surface morphology and self-healing properties of the coating at different temperatures were analyzed with a TESCAN S8000 (Tescan, Brno, Czech Republic) in situ high-temperature scanning electron microscope. Figure 2 shows the BMJ-01 aircraft wheels and tires 1:1 dynamic simulation test bench, which can fully simulate the actual braking conditions of the aircraft, and the brake test is completed according to CTSO-135a to verify the oxidation resistance of the aircraft brake discs.

Fourier transform infrared spectroscopy (FTIR): measurement was carried out with IS5 infrared spectrometer (Thermo Scientific, Waltham, MA, USA); thermo-gravimetric analysis (TGA) experiment: the spline was subjected to TG test using a SDTQ600 thermo-gravimetric analyzer (TA Instruments, Lukens, DE, USA). The temperature range was 50 °C–800 °C and it was tested under a nitrogen atmosphere with a gas flow rate of 20 mL/min; limiting oxygen index (LOI) test: the standard is ISO 4589-2 [16 ], and we used the HC-2 type limit oxygen index instrument (Jiangning Instrument Analysis Factory, Nanjing, China) was tested, the test sample size was 100 × 10 × 4 mm³; vertical combustion test(UL-94): a CFZ-2 horizontal vertical burner (Jiangning Instrument Analysis Factory, Nanjing, China) was used, and the test sample size was 125 × 13 × 3 mm³; cone calorimeter test (CCT): this employed the ISO 5660 standard [17 ], and a Govmark CC-2-2128 cone calorimeter (Deatak, McHenry, IL, USA)was used to test the combustion performance of phenolic resin and its composite materials in the atmosphere of 50 kW/m² heat flux. The size of the test sheet was 100 × 100 × 3 mm³. Scanning electron microscopy (SEM): the morphological structures of the char layer after the calorimeter test were observed by Zeiss EVO18 SEM, Oberkochen, Germany.

SEM images were taken with a Carl Zeiss Supra 40 field emission scanning electron microscope (2–5 kV, depending on the sample state). All samples were measured in the form of aerogels that were prepared by freeze-drying of the purified wet nanocomposite pellicles. All aerogel samples were sputtered with gold for 30 s at a constant current of 30 mA before observation. Transmission electron microscopy (TEM) images were acquired using a JEOL JEM-ARM200F transmission electron microscope (200 kV). XRD data were measured by a PANalytical X'pert PRO MRD X-ray diffractometer equipped with Cu Kα radiation (λ = 1.54056 Å). The samples were tested in the form of films prepared by hot-pressing of the purified wet nanocomposite pellicles. UV–vis spectra were recorded on UV-2501PC/2550 at room temperature (Shimadzu Corporation, Japan). TGA data were measured in a nitrogen atmosphere with a TA Instruments SDT Q600 thermogravimetric analyzer. All the samples were tested in the form of films.

Thermal stability of the different cellulose nanofibers was determined by TGA measurements using a SDT-Q600 Thermogravimetric analyzer (TA Instruments, New Castle, DE, USA). Experiments were carried out under N₂ atmosphere (flux of 100 mL min⁻¹) from room temperature to 700 °C at a heating rate of 10 °C min⁻¹.