Experiments using Simultaneous Thermal Analyzer

Comparison of commercial computer programs 467 4.10.2.1.2 Experiments using Simultaneous Thermal Analyzer... 

The experiments described in this section were performed using a Simultaneous Thermal Analyzer STA 780 (Stanton-Redcroft Ltd.). This instniment supplies the measuring signals temperature (T), weight (TGA), first derivative of weight with respect to time... 

Software only for the Simultaneous Thermal Analyzer STA 780 was available for kinetics according to Borchardt and Daniels. Similarly to the kinetics program according to ASTM E 698-79, only separately sampled DTA data can be processed using the Borchardt and Daniels program. The DTA data from simultaneous TGA/DTA experiments cannot be... 

Thermal gravimetric analysis and differential thermal analysis (TGA/DTA) can be performed by using a SDT 2960 Simultaneous Differential Thermal Analyzer (TA Instruments, Inc., New Castle, DE). The instrument was calibrated with gold supplied by Perkin-Ehner. Samples (70 mg) of as-prepared powders were hand-pressed in a 3 mm dual action die and placed inside Pt sample cups and heated at the rates of 10 K/ min from ambient temperature to 1400°C. The reference material was used as a pellet of a-alumina. A flow of synthetic air at 50mL/min was maintained during the experiments. 

The synthesis of 1,2, and 3 have been reported previously. All reactions were carried out in an inert atmosphere unless otherwise noted. Solvents were purified by established procedures. 1,3-Dichlorotetramethyldisiloxane and 1,5-dichlorohexamethyltrisiloxane were obtained from Silar Laboratories and used as received. -Butyllithium (2.5 M in hexane) was obtained from Aldrich and used as received. l,7-Bis(chlorotetra-methyldisiloxyl)-/w-carborane 1 was purchased from Dexsil Corporation. Hexachlorobutadiene was obtained from Aldrich and distilled before use. Cure and thermal analysis studies were performed on various mixtures of 1 and 3a in milligram quantities. Thermogravimetric analyses (TGA) were performed on a DuPont SDT 2960 Simultaneous DTA-TGA analyzer. Differential scanning calorimetry analyses (DSC) were performed on a DuPont 910 instrument. Unless otherwise noted, all thermal experiments were carried out at a heating rate of 10 °C/min and a nitrogen flow rate of 50 cc/min. 

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