Egbert Meissner

Technological parameters of pyrolysis of waste polytetrafluoroethylene

The results of the pyrolysis of waste polytetrafluoroethylene (PTFE) to the useful compounds: tetrafluoroethylene, hexafluoropropylene, octafluorocyclobutane and heavy ends (mainly 1- and 2-octafluorobutylene) are presented. The studies were carried out in a two-stage reactor, where the second stage also consisted of two sections. The influence of temperature, pressure, nitrogen flow rate, PTFE feed rate, and residence time of the pyrolysis products in the high temperature reaction zone on the yields of the resulting compounds was investigated. The optimum parameters for the synthesis of these compounds were established using process optimisation by the method of rotary-uniform design of experiments.

Oligomerization of hexafluoropropylene oxide in the presence of alkali metal halides

Oligomerization of hexafluoropropylene oxide in the presence of alkali metal halides Oligomers of hexafluoropropylene oxide are raw materials for the synthesis of compounds having unique properties such as high chemical and thermal resistance. Two basic parameters have influence on the process of hexafluoropropylene oxide oligomerization: the kind of the catalyst and the solvent. The temperature and pressure influence this process to a lesser extent. The influence of halide ions, the solvent and the temperature on the oligomerization of hexafluoropropylene oxide has been studied.

Oxidation of hexafluoropropylene with molecular oxygen

Oxidation of hexafluoropropylene with molecular oxygen The results of the oxidation of hexafluoropropylene (HFP) to hexafluoropropylene oxide (HFPO) have been presented. The oxidation was carried out in an autoclave within the range of temperatures of 120 - 170°C and in the presence of an organic solvent (carbon tetrachloride). Molecular oxygen was used here as an oxidizing agent. The influence of: the molar ratio of HFP/O from 13.4 to 4.09:1, the process temperature, the addition of inert gas (nitrogen) from 4 to 18 atm and the periodical dosing of oxygen were investigated. The functions describing the process were: the conversion of HFP and the yield of HFPO in relation to HFP consumed. The presented process is very interesting owing to a wide application of HFPO.

Polarity of fluorine-containing oxyethylates as determined by inverse gas chromatography

Abstract The polarity of fluorine-containing oxyethylates has been studied using inverse gaschromatography. Oxyethylene derivatives containing a short fluorocarbon chain (denotedas Group I) exhibit a slightly higher polarity at all temperatures than their analogues(Group II) having double-length fluorocarbon chains. The difference decreases, however,with increasing length of the oligo-oxyethylene chain. An increase in the average numberof oxyethylene units increases the polarity of the products. The changes in oxyethylatepolarity may be described by various parameters, i.e. the sum of the difference of theretention indices of the first five McReynolds solutes as determined on the examinedliquid phase and on squalane as a reference, the polarity index, the ϱ coefficient andthe dispersive interaction parameters.

Research on the influence of parameters on hexafluoropropylene oxide oligomerization in the presence of complex amines

Research on the influence of parameters on hexafluoropropylene oxide oligomerization in the presence of complex amines Oligomers of hexafluoropropylene oxide were tested as potential materials for obtaining vari-ous compounds with unique properties, of which most important are chemical and thermal re-sistance. Two basic parameters influence the oligomerization process of hexafluoropropylene oxide: the type of the catalyst and the type of the solvent. Other parameters such as temperature and pressure have significantly less influence. The influence of tertiary amines as catalyst, the type of the solvent, temperature, pressure and catalyst concentration were tested in the process of hexafluoropropylene oxide oligomerization.