Dynamic thermogravimetric analysis

In dynamic thermogravimetric analysis a sample is subjected to conditions of predetermined, carefully controlled continuous increase in temperature that is invariably found to be linear with time. 

The primary thermal characteristics of the polyimides were determined by dynamic thermogravimetric analysis (TGA) as well as thermomechanically. Although the data for dynamic TGA should be treated with some reservation, one can conclude the following ... 

The glass transition temperatures ofthe polyimides are 195-250 °C their 10% weight loss temperamres (dynamic thermogravimetric analysis, air, AT = 4.5 °C/min) are 390-422 °C. Of particular interest are the dielectric constants of these polyimides. At a relative humidity of 50% these constants are 2.70-2.90 and are comparable with constants of the best fluorinated polyimides [21, 50-55]. The lowest dielectric constant (2.70) was observed for polyimide based on 6F dianhydride, containing the highest amount of fluorine. Thermal treatment of this polymer film at 280-290 °C for 1 hour led to a decrease (2.45) of dielectric constant due to the possible formation of nanofoams [56]. 

Thermal stability is an important criterion for microelectronic applications and hence has been the focus of several studies. Figure 9 shows the dynamic thermogravimetric analysis (TGA) of Parylene-N in both inert and oxygen environments. It is clear that, Parylene-N is stable up to about 480°C in inert ambient, beyond which it gradually decomposes. 

Isothermal methods have generally been used for the study of thermal degradation mechanisms and the determination of kinetic parameters. In recent years, however, dynamic thermogravimetric analysis (TGA) has been developed. In this case, polymer samples are weighed in a... 

Thermogravimetric analysis Dynamic thermogravimetric analysis Differential thermogravimetry Differential thermogravimetric analysis... 

The thermal stability of the (alkylsulfonyl)methyl-substituted polymers was evaluated from dynamic thermogravimetric analysis (TGA) under N2 (Table II). All the (alkylsulfonyl)methyl-substituted polymers were stable to 300 C. Figure 3 shows that all of the (alkylsulfonyl)methyl-substituted polymers have similar decomposition behavior their initial decomposition and half decomposition temperatures were very close. Table III shows that the side chain length does not affect the thermal decomposition behavior. Backbone structure does affect the decomposition behavior slightly. MST shows a two-step decomposition and MSEE shows the highest thermal stability (Figure 4) of the three (methylsulfonyl)methyl-substituted polymers. 

L. Reich and D. W. Levi, Dynamic thermogravimetric analysis in polymer degradation, Macromol. Rev. 1, 173(1967). 

Radhakrishnan and Rao [1] have studied the kinetics and mechanism of the degradation of thiol terminated polysulfide polymers HS(RSS) RSH, R-CH -CH OCH -OCH -CH - which have been cured with ammonium dichromate using pyrolysis-gas chromatography (Py-GC) and isothermal and dynamic thermogravimetric analysis (TGA). 

Figure 5 Dynamic thermogravimetric analysis of polyphenylquinoxaline 15 in argon (a) and in air (b) at a heating rate of 10°C min...

Figure 24 Dynamic thermogravimetric analysis of conductive adhesives (a) Al-filled IP 675 in air and Au-filled IP 685 in argon (b) Ag-filled IP 680 in argon (c) IP 680 and IP 685 in air (d) Ag-filled IP 670 epoxy adhesive in air.

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