Courageous Questioning of Established Thinking: The Life and Work of Hermann Staudinger

Abstract

Hermann Staudinger (23.3.1881–8.9.1965) gave plastics chemistry its theoretical foundations. Although his outstanding career as a scientist – doctorate at 22, professorship at 26 – culminated in the Nobel Prize in Chemistry, Staudinger has remained largely unknown (as a public figure too) and nowadays only specialists are familiar with his life and work. In 1920, Hermann Staudinger published his “Macromolecular manifesto”, which gave plastics chemistry its foundations but was rejected resoundingly by the organic chemistry establishment. The opposition that Staudinger faced as a result threatened to isolate him, but he defended his theory stubbornly and continued his attempts to prove experimentally the existence of the “giant molecules” he had postulated in theory.

Hermann Staudinger started a new phase of his life in the 1930s: his theory about the macromolecular structure of polymers, which was hotly contested in the initial stages, finally received the recognition it deserved. While the opposition he faced from the scientific community decreased, new storm clouds developed in 1933, when the Nazis assumed power. Staudinger’s life’s work culminated in the Nobel Prize in Chemistry, which he received from the Swedish King on 10 December 1953. This was late recognition for a 72-year-old retired professor, who no longer represented the avant-garde of his subject but whose achievements are still being acknowledged. This article aims to rectify this. It portrays Staudinger as a productive and unorthodox thinker, who refused to accept conventional arguments in both his scientific and political activities – until his ideas finally became mainstream convictions.

Appendices

Appendix 1

Addition is the name given in chemistry to a process in which a new substance is formed from two other substances without any by-products. In addition polymerisation, molecular components or monomers with different structures are linked to create high polymers with the migration of hydrogen atoms. This type of polymerisation is generally carried out by subjecting the monomers to heat and pressure. Two significant groups of plastics are manufactured by this process nowadays: polyurethanes and epoxy resins. Condensation polymerisation can take place when the reactants each have two functional groups that can combine with each other by producing water. Staudinger ([1], p. 108) writes: “Condensation polymerisation is characterised by a chemical reaction between two compounds with groups that are of the same or different kinds but are reactive, in which […] there are low-molecular by-products such as water, alcohols, ammonia, hydrochloric acid or similar substances. […] It is an absolute technical necessity for the by-products of the reaction to be removed in the condensation process […] for the reaction to go smoothly and successfully. The list of technically important plastic groups that are manufactured by the condensation polymerisation process includes the following: (1) the group of phenol formaldehyde resins (i.e. typical duroplasts such as Bakelite); (2) polyamides (nylon and perlon) and linear polyesters (particularly polycarbonates as thermoplastics); and (3) crosslinked polyesters as lacquer and casting resins. […] (In addition to this list, editor’s note) silicones”.

Appendix 2

Initiators are substances that need to be present to produce certain high polymers. They help to bring about polymerisation and can appear in the end product – in contrast to catalysts (reaction accelerators). Although the latter are involved in the chemical reaction temporarily, they are unchanged by it.

Appendix 3

The Swiss botanist Carl Wilhelm von Nägeli (1817–1891) coined the term “micelle” (from the Latin word micella, meaning “crumb”) in the nineteenth century. His studies about starch, cellulose and various types of protein led him to assume that “organised bodies”, i.e. substances extracted from biological systems, consisted of aggregates that were in turn made up of molecules. Nägeli named these aggregates, the size of which was between molecules and visible crystals, micelles. Staudinger [10, pp. 8–9] writes: “[…] numerous small molecules are held together by weak inter-molecular forces in a micelle; an increase in temperature or a change in solvent can already cause them to disintegrate as a result.”

Appendix 4

Letter of 2 November 1928 from Hermann Mark to Hermann Staudinger (excerpt; quoted in [15], pp. 93–94):

I was sorry to read in your letter that you feel your priority has been violated by the statements made by Professor Meyer. I am convinced that nothing was further from Professor Meyer’s mind than this and I myself have also tried especially hard to emphasise the importance of your fine work appropriately, not only in our work but also and in particular in my lecture in Hamburg.

I do, however, consider it sensible to introduce the word ‘primary valence chain’, because it refers to structures that are not completely identical to what has been called a molecule up to now. I always associate the word ‘molecule’ with the concept of a large number of completely identical structures, whereas the term primary valence chain is specifically supposed to include the fact that the same substance contains structures that are very similar to each other, cannot be separated from each other by chemical methods but differ from one another a little in their size, so that while it is not possible to indicate a precise molecular weight, an average primary valence chain length can be quoted. If this fact is specifically added to your macromolecule, then the two terms are, as far as I can see, identical and it is a question of convenience whether one says ‘primary valence chains’ or ‘macromolecules of fluctuating size’.

For this reason, I would not want to stress this difference too much; I think that it is much more expedient and much more appropriate to the situation if we agree that we essentially think the same, i.e. that the chemical primary valences play a crucial role in the structure of high-polymer substances. I consider it less important that we give different names to the intermediate factors. The main issue in the near future will, after all, be whether the positions held by you and us as well as Freudenberg, Willstätter and others prevail or whether the people will be proved right who think that it is necessary to assume new kinds of association forces not yet detected in chemistry up to now in order to explain everything that we have experienced. I think that we should proceed together in commenting on this issue and should not emphasise certain differences between our personal views that are in my opinion minor; if we did, the high-polymer community could easily make the mistake that is only too familiar from politics; that a major issue was not given close enough attention and was not presented clearly enough because of minor differences between opinions that were not far apart.

I will try and find a way to come to Freiburg again as soon as possible, because I would like very much to talk to you in detail about this issue.

Until then I remain

yours sincerely,

H. Mark

Appendix 5

1.1 Nomen est Omen

Hermann Staudinger’s memory is kept alive not least of all by the various uses to which his name has been put. Although they enhance scientific vocabulary in particular, one comes across them in day-to-day life as well, because schools and roads are among the things that have been named after Staudinger. Here is a short list:

• Staudinger reaction

• Staudinger synthesis

• Staudinger index: The relationship between the viscosity and the molecular mass of dissolved polymers

• Hermann Staudinger Prize: Endowed by BASF AG at the Society of German Chemists (GDCh) and awarded for the first time in 1971

• Roads: Roads named after Hermann Staudinger (with and without his first name) can be found in Baden-Württemberg (Emmendingen, Freiburg, Karlsruhe, Münsingen, Waldshut-Tiengen), Bavaria (Aschheim, Helmbrechts, Munich, Rehau, Trostberg, Viechtach), Hamburg, Hesse (Bürstadt, Darmstadt, Rodgau, Viernheim), Lower Saxony (Braunschweig, Lage/Lippe), North Rhine-Westphalia (Gütersloh, Velen) and Schleswig-Holstein (Norderstedt).

• Schools: Staudinger Primary School and Carmelite/Staudinger-Realschule plus (former Staudinger-Hauptschule) in Worms, the city where Hermann Staudinger was born on 23 March 1881; Hermann-Staudinger-Realschule in Konz/Rhineland-Palatinate; Staudinger Comprehensive School in Freiburg im Breisgau; Hermann Staudinger Grammar School in Erlenbach/Bavaria; and Hermann Staudinger Graduate School at Albert Ludwigs University in Freiburg im Breisgau

• Staudinger cactus: Echinopsis × Trichocereus Multihybrid Hermann Staudinger with large flowers, hybrid BS.1491/2006 (breeder: Ingo Bartels, Burgdorf)

• Hermann-Staudinger-Haus: The building is in Freiburg im Breisgau: it was established in 1962 and houses the Freiburg University Institute of Macromolecular Chemistry. The American Chemical Society and the Society of German Chemists unveiled a plaque in honour of Hermann Staudinger here on 19 April 1999. This plaque says:

Historic International Milestone in Chemistry – Origin of Polymer Sciences. Albert Ludwigs University, Freiburg, Baden-Württemberg, 1926–1956: This building has been named after Hermann Staudinger, who carried out his pioneering research on macromolecules in Freiburg from 1926 to 1956. His theories about the polymer structure of fibres and plastics as well as his later studies of biological macromolecules formed the basis for countless modern developments in the materials and biosciences and supported the rapid growth of the plastics industry. Staudinger received the Nobel Prize in Chemistry in 1953 for his work in the polymer field.