Controlled rate thermogravimetric

A technique called evolved gas analysis is used to monitor the by-products of reactions associated with heat (Chapter 4). In this technique the sample is heated at a controlled rate under controlled conditions and the weight changes monitored by, for example, thermogravimetric analysis. 

Thermogravimetry (TG) data were obtained on the NH4+- and H30+-exchanged ZSM-5 samples, as well as on a separately prepared NH -exchanged sample of similar composition, for confirmation purposes. A duPont Model 951 thermogravimetric analyzer was used in conjunction with a Model 990 Recorder-Controller. The TG curves were obtained on approximately 25 mg samples, at a heating rate of 10°C per minute, and under flowing air at a rate of 38 cnP per minute. 

Thermogravimetry (TG) or thermogravimetric analysis (TGA). In this technique, the mass of a sample is followed as a function of temperature or time. The amount and rate of mass change with temperature or time in a controlled atmosphere are obtained. Such information can tell us about thermal stability as well as the compositional profile of a variety of elastomers and polymers. It is an excellent quantitative technique but qualitatively there may be some doubt as to what material is lost during heating. 

Thermogravimetrical analysis (TGA) This technique is widely employed and it measures the amount and rate of change in the weight of a material as a function of temperature under a controlled atmosphere. The measurements are used primarily to evaluate the thermal stability. The technique can characterize materials that exhibit weight loss or gain dne to decomposition, oxidation, or dehydration. As an example, Zhang et al." evaluated the step thermal degradation and the thermal reliability of a silica/n-octadecane MPCM. 

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