Fill time pyrolysis

Accordingly, a 0-1 molar solution of phthalic anhydride in benzene (100 ml.) was pyrolyzed at 690° under nitrogen at a steady rate of 30 ml/hr (Fields and Meyerson, 1965). The pyrolysis tube was Vycor, filled with Vycor beads contact time was 11 5 sec, which gave a 58% conversion of the phthalic anhydride. Acetylene was steadily evolved, along with carbon dioxide and carbon monoxide in a 1 1 ratio these were identified in the gas stream by mass-spectral analysis of samples taken at regular intervals. The benzene was distilled off and the products boiling over 180° (2 g) were analyzed by mass spectrometry on a Consolidated Model... 

For substrates with extremely low volatility, Staab et al. used a modification of the standard procedure [18], which has been successfully applied for the synthesis of kekulene [19]. A closed and evacuated valve filled with the substrate is introduced for 3-5 min in a preheated air-bath (ca. 500 °C). Pyrolysis does occur in the solid phase, not in the gas phase. However, the sulfur-free products sublime more easily than the starting material and after a short time they condensate at a cooling device outside the reaction vessel, where the work-up can be carried out as usual. Yields are low for this modification nevertheless, for substrates with extemely low volatility (and extremely low solubility of the sulfides as well) this often is the only choice available. 

To address the temperature issues related to excess silicon, all the same constituents in the N24-C system are used for potential N26 CMC generations, but remaining open pores in the CVI SiC matrix are filled by silicon-free ceramics, rather than by melt infiltration of silicon. In particular, for the N26-A CMC system, a SiC-yielding polymer from Starfire Inc. [13] is infiltrated into the matrix porosity at room temperature and then pyrolyzed at temperatures up to 2912°F (1600°C). This polymer infiltration and pyrolysis (PIP) process was repeated a few times until composite porosity was reduced to 14 vol,%, At this point, the total CMC system is then thermally treated at NASA to improve its thermal conductivity and creep-resistance. Thus although more porous than the other CMC systems, the N26-A system has no free silicon in the matrix, thereby allowing long-time structural use at 2600°F... 

First, selected coals are blended and pulverized. Some coal tar is added for appropriate bulk density control. The blended coal is charged into the coking chambers by a charging car, which moves on the roof of the coke oven battery in a longitudinal direction, and the chambers are filled from the top in a specific sequence via charging holes. The brick walls of each coking chamber are heated up to about 1100 °C and, in the course of time, the coal charge is heated and transformed by pyrolysis... 

A 10% solution of each hexafluoropropylene-vinylidene fluoride copolymer is prepared by dissolving 10 g of polymer in 100 ml of reagent grade acetone. A vial 58 mm high is filled with the sample solution. A pyrolysis wire, previously cleaned in a bunsen burner until red hot, then cooled, is dipped into the vial. The dipped wire is then dried in a vacuum oven at 90°C for 30 min. Use of lower drying temperatures or shorter times results in an acetone peak in the pyrogram. This is due to mechanically trapped... 

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