Stanton Redcroft

The Model STA-700 series of instruments for TG and simultaneous TG-DTA have been described in Chapter 3. The systems have maximum furnace temperatures of 1000 or 1500 C. Also available are ihe DTA 670 series DTA instruments for use in the temperature range of -150 to 1650 C, and the TA 680 series usable in the temperature range from 25 to 1650°C, A wide variety of sample holders and furnaces are available for each series. 

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Thermal gravimetric analysis (T.G.A.). measurement of the weight loss, as a function of temperature, of some of the SiC -g-PS samples was carried out using a Stanton Redcroft TG 750 instrument at a heating rate of 5° min- under a nitrogen atmosphere, and at a gas flow rate of 20 cm min-. ... 

Flammability. Flammability of the samples, in the form of thin strips of approximate dimensions of 120mm x 7iun x 3mm was determined by measurement of their oxygen indices (01 s) according to ASTM D2863, using a Stanton-Redcroft FTA module. 

It has been established that the 01 values of polymers fall, in some cases dramatically, when the surrounding gas mixture is heated ( ] ). Consequently, the 01 test has been extended to materials at elevated temperatures, and the high temperature 01 s of polymer samples were determined using a Stanton-Redcroft HFTA instrument. 

The adsorption isotherms of xenon were measured at 34°C using a classical volumetric apparatus. The 29xe-NMR measurements were performed at the same temperature on a Bruker CXP-200 spectrometer operating at 55.3 MHz. The n-hexane adsorptions were conducted at 90°C on a Stanton Redcroft STA-780 thermoanalyzer. The samples were submitted to a preliminary calcination under dry air up to 650°C with a heating rate of 10°C/min. 

The identification of the solid phases and the evaluation of their crystallinity were performed by X-ray powder diffraction while the pore volume of the ZSM-48 materials was evaluated by isothermal (90 °C) sorption of n-hexane, followed in the thermobalance (Stanton Redcroft ST-780 combined TG-DTA-DTG thermoanalyser). 

Thermogravimetric analysis was performed on a Stanton Redcroft thermobalance in a flowing oxygen atmosphere at a heating rate of 10°C/minute. Thermal desorption/mass spectrometry (TD/MS) was carried out using am Extranuclear quadrupole mass spectrometer. 4 ... 

Stanton-Redcroft Ltd., Copper Mill Lane, London SW17, England. 

DSC thermograms were recorded on either a DuPont 900 or a Stanton Redcroft STA 785 + CPC 706 instrument with a heating rate of 20°C/min. TGA thermograms were determined with the Stanton Redcroft instrument. Thermal transitions were also studied using a Linkam... 

Testing procedure. The minimum concentration of oxygen is measured using a vertically suspended sample in an instrument capable of modifying the atmosphere by mixing oxygen and nitrogen in required proportions (e.g., Stanton Redcroft instrument). The result of determination is presented in a form of % Oj. 

Thermogravimetric analyses were carried out on a Stanton Redcroft TG770 thermobalance with a Bausch and Lomb Omnigraphic 2000 XY Recorder. Approximately 8mg of catalyst was heated at a rate of 10°C min in a flow of 30 mis min air from 20°C to 900°C. 

Calibration of the TPC runs was performed on a Stanton Redcroft TG750 thermobalance. A 12.5 mg sanple of Co/Ti02 was reduced in flowing H2 at 400°C and then carbided in pure CO at a heating rate of 5°C/min. 

The tpd profiles were determined using a Stanton-Redcroft TG 762 thermogravimetric balance with on-line Commodore CBM computer for data collation and analyses.(3.4) The profiles were analysed using the single heating rate, variable coverage (SHR) method. (4.)... 

Figure 3>27. Schematic diagram of Stanton Redcroft Mode) TG-750 thermobalance.

Figure 3.28. Cross section of Stanton Redcroft TG-DTA 1500CC furnace. 

Dunn. J. G-. Tech. Inform. Sheet So. J04, Stanton Redcroft, London. 

Figure 5.21. Commercial DTA sample holders evaluated by Dollimore et at. (139). ( ) Netzsch standard cell (nickel block, wells approx. 8 mm in diameter) (/>) Stanton Redcroft cell (aluminum pans, approx. 6 mm in diameter) (e) Netzsch catalytic cell (ceramic sleeves, approx. 8 mm in diameter) (d) Du Pont intermediate temperature cell (sample tube approx. I mm in diameter) (e) Wilburn cell (nickel block, wells approx. 9 mm in diameter) f) Du Pont high-temperature cell with platinum liners in place (sample holder approx. 5 mm in diameter) Arrows indicate normal direction of gas flow.

Stanton Redcroft DTA 671. With an undiluted sample (d), the peak splitting is apparent Using a diluted sample (c), the splitting is reduced... 

Figure 5.22. DTA curves for the dehydration of UOzCjO -3H.O using various DTA sample holders (139). a. Netzsch standard cell, diluted sample, 300 mL min 1 nitrogen over sample b. Netzsch catalytic cell, diluted sample, 500 mL min-1 air over sample. c. Netzsch catalytic cell, diluted sample, 5 mL min 1 air through sample d. Stanton Redcroft cell, undiluted sample. 25 mL min 1 air over sample e, Stanton Redcroft cell, diluted sample, static air /. Stanton Redcroft cell, diluted sample, 10 mL min-1 nitrogen y, Du Pont intermediate temperature cell, undiluted sample, 400 mL min-1 nitrogen over sample A, Du Pont intermediate temperature cell, undiluted sample, in vacuo (1.9 kN m-2) i. Du Pont high-temperature cell, with liner, diluted sample, 500 mL min"1 air over sample / Du Pont high-temperature cell, without liner, diluted sample, 500 mL min"1 air over sample. Diluted samples 20% w/w with -Al,Oj. peak temperatures in K.

Tech. Inform. Sheet No. 15, Stanton Redcroft Ltd., London. 

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