Johannes Pfleger
Johannes Pfleger (born September 11, 1867 in Dansenberg ; † August 8, 1957 in Rheinfelden (Baden) ) was a German chemist .
Pfleger went to the industrial school in Munich when he graduated in 1884 and studied chemical engineering at the Technical University of Munich from 1886 to 1891 after completing his military service. During his studies he became a member of the Cimbria Hanover fraternity . From 1891 he was a chemist at Degussa in Frankfurt am Main , where a year later he took over the experimental station for electrochemistry and electrometallurgy (which was operated by Degussa and the Metallgesellschaft). In 1900 he became head of the testing department at Degussa and research chemist . He played a key role in establishing chemical research (and in general chemistry in addition to precious metal separation) at Degussa and became chief chemist in 1921. In 1933 he retired, but was a freelancer until 1942.
Pfleger improved the Castner-Kellner process for the production of sodium cyanide at Degussa with a process that was used until 1971.
He is known for his contributions to the improvement of the (first) indigo synthesis according to Karl Heumann (production from N- phenylglycine in alkali melt). Although it had been known since 1890, its yields were too low and only became economical thanks to the condensation agent sodium amide introduced by Pfleger in 1901 and therefore also called Heumann-Pflegeer's indigo synthesis (or Pflegeer's indigo process, patented in 1901). Sodium amide was an intermediate in the Castner-Kellner process. Degussa marketed the patent with the paint manufacturer, Meister, Lucius and Brüning, later Farbwerke Hoechst , and received very high dividends (up to 30 to 50% between 1906 and 1911).
Chemical bleaching processes were another important research area for Pfleger for Degussa.
In 1911 he became Dr. Ing. E. H. at the TH Munich and in 1923 he received an honorary doctorate from the University of Frankfurt. In 1931 he was made an honorary citizen of the Berlin Agricultural University for contributions to pest control.
literature
- Winfried R. Pötsch (lead), Annelore Fischer, Wolfgang Müller: Lexicon of important chemists , Harri Deutsch 1989, p. 72
Web links
References and comments
- ^ Directory of the old men of the German fraternity. Überlingen am Bodensee 1920, p. 278.
- ↑ There is a second Heumannian indigo synthesis .
| personal data | |
|---|---|
| SURNAME | Nurse, Johannes |
| BRIEF DESCRIPTION | German chemist |
| DATE OF BIRTH | September 11, 1867 |
| PLACE OF BIRTH | Dansenberg |
| DATE OF DEATH | August 8, 1957 |
| Place of death | Rheinfelden (Baden) |