At the Polytechnic Institute in Brooklyn, Hermann Mark was assigned to what was known as the Shellac Bureau in September 1940. This laboratory, which was funded by the US Shellac Import Organization, was responsible for the control and chemical characterisation of deliveries of shellac when they arrived from India and Indonesia (Mark 1993, 93 and Deichmann 2001, 184). Since imports declined because of the war and the trade routes across the world’s oceans were no longer safe, the head of the Shellac Bureau, William Howlett Gardner (1902-1993) tried to find natural or synthetic substitute materials that the US companies which processed shellac could be supplied reliably. A project for which Hermann Mark was eminently suitable:
“During my years in Ludwigshafen, I was well informed about synthetic resins with properties similar to and even superior to those of shellac. During my consulting years with I. G. Farben (1932-1938), I had kept up with progress in the field. Several vinyl ester polymers […] together with polyacrylic and polymethacrylic esters […] were close to natural shellac in many respects. Specifically, from 1928 to 1932 we had carried out work on the synthesis, characterization and application of such systems in other units of the company, Farbwerke Hoechst and Wacker Chemie. They had worked out useful copolymers and polyblends, not only for the replacement of shellac but also for the preparation and production of an entire family of soluble resins. […] It was a lucky coincidence that I was able to transfer from Germany to the United States a science and technology that was interesting and valuable for my new employer“ (Mark 1993, 93-94).
In 1942, Mark was appointed a full professor. Soon afterwards, he received approval from Dean Raymond Kirk (1890-1957) to establish a research centre for polymer chemistry with associated teaching operations at the Polytechnic Institute, “the first graduate programme of this kind at an American university” (Deichmann 2001, 184). As the Polymer Research Institute, it replaced the Shellac Bureau (Mark 1978, 124). “In contrast to other institutes […], which specialised either in the synthesis or the properties of polymers, Mark tried to cover all aspects of polymer chemistry. By bringing physicists, chemists and technicians together, he succeeded […] in establishing modern polymer science as a multidisciplinary branch of academic research” (Deichmann 2001, 184-185) – modelled on the Kaiser Wilhelm Institutes and facilities in Germany (Mark 1993, 104). In the “pioneering activities” carried out by the Polymer Research Institute, the research scientists – including some of Mark’s former students from Germany or Austria – concentrated on analysis of the different polymerisation processes (photo, emulsion and suspension polymerisation as well as – later on – solid phase and high-speed polymerisation) and on structural information, molecular weight and viscosity measurements of high polymers (Mark 1978, 123, Mark 1993, 95 and Beneke 2005, 13).
In Hitler’s Germany, Mark had in the meantime been deprived of his citizenship and he was stripped of his doctorate on 7. November 1944. Astonishingly, two texts written by Mark had succeeded in being published beforehand, in spite of ubiquitous censoring: in 1939, a volume of lectures was published by the Viennese company Franz Deuticke that included Mark’s contribution “Small causes – large effects in the progress made in natural sciences” and in 1940, Akademische Verlagsgesellschaft in Leipzig published the 345-page monograph “General basics of high polymer chemistry”.
As an exile, Mark had no inhibitions about holding lectures worldwide and maintaining contact with polymer research scientists all over the world, in order “to create an international community of polymer scientists” (Deichmann 2001, 186). During his time in Vienna from 1932 to 1938, he had developed into an international player in the new polymer sciences field, when the Nazis were already in government in Germany. There were strict rules about foreign travel by scientists in Germany, to the detriment of the “father of macromolecular chemistry” too – Hermann Staudinger, who was based in Freiburg im Breisgau and was even subject to a travel ban for years. In the USA, Mark continued to drive the internationalisation of his field:
“Toward the end of the war […], my main concern was to make the work and our institute internationally known. I planned to initiate and sponsor the founding of similar institutions that would constitute a network of polymer research centers cooperating as closely with each other as the prominent schools of organic chemistry did in Oxford and Munich“ (Mark 1993, 103).
As mobile as molecules
Mark’s extramural activities took him to such places as Europe, Japan and the Soviet Union (Mark 1978, 128); in spite of the Cold War, Mark – who held an American passport too in the meantime – became a foreign member of the Soviet Academy of the Sciences. In Israel, he established a polymer research programme as Chairman of the Committee for the Foundation of the Weizmann Institute (Deichmann 2001, 185; for details, see Mark 1993, 103-107). All in all, Mark undertook more than 500 trips abroad during his career and visited more than one thousand scientists in the course of them (Beneke 2005, 12). Mark commented humorously on the fact that he was constantly on the move by comparing it with Brownian molecular motion: “I do not travel, […] I’m being traveled. It is a form of Brownian motion!” (Mark 1993, XXI). Mark’s extensive publishing and editing activities were, incidentally, targeted at the global community of polymer research scientists too: in 1940, he launched the monograph series “High Polymers and Related Substances” in the newly established publishing company Interscience, the first volume of which was devoted to the work of Wallace Hume Carothers (1896-1937), the Du Pont employee who invented nylon. In 1946, Mark co-operated with the chemist and publisher Maurits Dekker (1899-1995) and the chemist Eric S. Proskauer (1903-1991) to launch the “Journal of Polymer Science”.
After the end of Nazism, more and more people in Austria started to remember Mark again. On 8. April 1946, the Philosophy Faculty at Vienna University campaigned for the return of four exiled natural scientists, including Hermann Mark (Reiter 2017, 416). He did not have any reservations: although it was to take until 1955, before he acted as guest professor for the physical chemistry of high polymers for a term at Vienna University, particularly in view of the fact that the latter took just as long to recognise his doctorate again. He did, however, travel to Vienna again as early as 1947 and contacted Professor Ludwig Ebert (1894-1956), who had taken over the Chair at Chemical Institute I that Mark had vacated in 1938. Mark assured Ebert that he would not force him out of this position and confirmed that he had performed well in it (Mark 1993, 86). Ebert had not been a member of the Nazi party. However, Mark did have to work on the constant assumption that he would come across former Nazis and personal opponents in Vienna, although he was not afraid of such encounters: “Mark’s willingness to forget unpleasant things included his contacts to former Nazis. In this respect, he was an exception among the emigrants” (Deichmann 2001, 186). Mark did not hold grudges; he neither complained about his fate nor did he make accusations against anyone. His first-born son, Hans Mark, reported that his father had deliberately taken the decision not to make the past the yardstick for the future (Mark 1993, XXIII). On the contrary, he was more interested “in quickly integrating colleagues from Germany in the international community of polymer scientists too” (Deichmann 2001, 187). At his Polymer Research Institute in Brooklyn, for example, Mark hosted people with such severe political liabilities as the chemist Kurt Hess (1888-1961), “who was not only a former member of the Nazi party, the SA and the SS but had also denounced (the nuclear physicist, editor’s note) Lise Meitner (1878-1968, editor’s note) as a Jew” (Deichmann 2001, 186). Mark was charitable in describing Nazis as “misguided” and scientists who served them as “unfortunate”: “He doesn’t seem bitter, yet he has a right to be” (Mark 1993, 86). Herbert Morawetz (1915-2017), one of Mark’s contemporaries at the Brooklyn Institute, thought that “one of the driving forces behind Mark’s remarkable attempts to establish or re-establish good relationships to colleagues irrespective of their political background and earlier enmity was his desire to be ‘the father of polymer chemistry’. He did not therefore allow politics of any kind to obstruct his work” (Deichmann 2001, 187). In the light of this, it is understandable why Frederick Roland Eirich (1905-2005), who also taught chemistry in Vienna until 1938 and accepted an appointment in Brooklyn after the war, described Mark not only as a significant chemist but also as just a great a politician (Deichmann 2001, 186).
What Mark and Staudinger agreed about
Mark did not attempt to avoid Hermann Staudinger after 1945 either, even though the latter had battled him vehemently and after 1933 had even disparaged him as the spearhead of alleged Jewish scheming against his person (Deichmann 2001, 407). In actual fact, Mark was one of the first chemists in Germany in the 1920s who did not reject Staudinger’s macromolecule concept out of hand; he had instead supported it, albeit not uncritically – as was appropriate for a scientist. Staudinger found it difficult to deal with criticism, however, tending to divide the world up into friends and enemies (Lindner 2005, 296) and treating anybody who failed to concur with him unconditionally as an opponent. He also had a strong need for recognition and admiration. Staudinger considered colleagues who were also professors and worked in his field to be intruders, competitors or plagiarists and rarely accepted them as potential allies. Hermann Mark at any rate saw himself as one of the latter when he spoke about the X-ray structural analyses he had made of high polymers at the 89th meeting of the Society of German Natural Research Scientists and Doctors in Düsseldorf from 20. to 24. September 1926 and ended by concluding that his results were consistent with Staudinger’s macromolecule hypothesis. He explained that the small elementary bodies made visible in X-ray images of crystals were not at any rate an argument against the possibility that “the entire crystallite” is a single “large molecule” (quoted from Deichmann 2001, 253). An insult to most of the chemists at the meeting, who thought that they could expose supposed huge molecules as combinations of small molecules, held together by weak bonding forces (secondary valences) – a position that Kurt Hess, who has already been mentioned and was one Staudinger’s keenest opponents, adopted with respect to cellulose (see Deichmann 2001, 403-408). In contrast to this, a macromolecule is by definition something integrated, a kind of threadlike or chain molecule that is held together by strong bonding forces (primary valences) that defy external influences. Historically speaking, the controversy can be summarised as follows:
“Until about 1920, it was accepted in research and teaching that substances like cellulose and proteins were close to synthetic compounds with a high molecular weight and were therefore considered to be very high molecular. […] In the years 1920-1934, a number of research scientists (then, editor’s note) held the view that such natural substances as cellulose, rubber and starch consist of small molecules that are characterised by special association forces that are peculiar to them alone as well as by high association due specifically to these forces […]. In spite of the arguments in favour of ‘small, high-association components’, most experts, including, for example, […] H. Mark, K. H. Meyer, […] H. Staudinger […] continued to adhere to the ‘classic’ position. It gradually became clear that none of the arguments presented in favour of ‘small components’ was sound; some observations were not confirmed in subsequent tests, while others […] received interpretations that were consistent with the assumption of very large molecular weights. However, what were crucial for the question whether primary valence bonds or association forces hold the residue together in cellulose or protein were research into and systemisation of the bonding forces that existed between atoms […]. High-strength bonds that require both substantial amounts of energy and considerable activation heat to be separated can be described unhesitatingly as covalent primary valence bonds. As a result, the theory of small, associating molecules can be considered as abandoned and of merely historical interest” (Meyer, Mark and van der Wyk 1950, 2-3).
Staudinger was the first chemist to confirm the existence of macromolecules experimentally. To do this, he examined synthetic molecules, whereas Mark and Kurt Heinrich Meyer, his boss at BASF, concentrated primarily on such natural high polymers as cellulose, which Staudinger did not investigate until after 1929 (Deichmann 2001, 254). In addition to this, Staudinger preferred to examine polymers in solution, in order to draw conclusions about the molecular structure from their viscosity level, while Mark focussed primarily on crystal structures in their solid aggregate state (Mark 1926, 436). This means that the organic chemist Staudinger and the physical chemists Mark and Meyer used completely different methods to prove the existence of macromolecules. As of 1922, Mark specialised in crystal structure analyses via X-ray fractometry at the KWI for Fibre Chemistry in Berlin-Dahlem. This came about as follows:
“After the war, the German chemical industry had been forced to take over the nitrocellulose factories (which produced explosives, editor’s note). Since they were not of course allowed to manufacture nitrocellulose, they tried artificial silk instead. The products this led to were not satisfactory, however. Professor Haber said to my Viennese boss, Professor Schlenk, at the time: ‘I am convinced that more needs to be found out about the structure of the fibres. There is a method: analysis with X-rays. Now, I have enough physical chemists and physicists in Dahlem, but cellulose and silk are organic substances. I need an organic chemist. Do you have an organic chemist who is interested in physics?’ And Schlenk called me to tell me this. […] That is how I ended up in Dahlem” (Kreuzer 1982, 45-46).
What Mark and Staudinger disagreed about
Although Staudinger had proved the existence of macromolecules perfectly satisfactorily, Mark did not think that one should stop there: “It is no help to us to know that a molecule has a molecular weight of a hundred thousand. […] We need to know: how are the individual atoms joined together? Is it a chain or does it look like a Christmas tree? That was the burning question at the time and X-ray analysis was the only way to find this out. […] X-rays provide a diffraction image, i.e. a large number of speckles, and if they are measured precisely with respect to their location and intensity, it can be calculated where the atoms must be, so that they produce this image” (Kreuzer 1982, 48-49). This image, i.e. more exact information about the structure of cellulose, silk or rubber, could then be used to draw the decisive conclusions for “molecular engineering” – which has already been explained – i.e. to answer the key question: “What must […] synthetic( ) molecules look like that have similar properties?” (Kreuzer 1982, 50).
So although Mark basically agreed with Staudinger, he felt that the latter’s macromolecular concept was not nuanced enough and therefore needed to be expanded. The criticism in detail:
“The […] compounds obtained by Staudinger by polymerisation form merely one group of high-molecular substances” (Meyer and Mark 1930, 72). It was not therefore acceptable to apply results of work carried out on synthetic polymers to natural high polymers without modification (ibid., 71), e.g. to consider polyoxymethylene as a model for cellulose, as Staudinger had done (ibid., 91).
Certain polymers, e.g. the paraformaldehyde that was analysed by Staudinger, were “definitely not a uniform product; they were instead a blend of polymerisation products and/or of threadlike molecules or primary valence chains of varying length, so that the molecular weight determined only represents an average figure” (Meyer and Mark 1930, 66). In a letter to Staudinger of 2. November 1928, Mark therefore justifies introduction of the term “primary valence chain”. “I always associate the concept of a large number of completely identical structures with the word ‘molecule’, whereas the term ‘primary valence chain’ is supposed in particular to incorporate the fact that structures which are very similar to each other but cannot be separated from each other by chemical methods are present in the same compound. The size of these structures varies a little, however, so that a precise molecular weight cannot be specified, while it is on the other hand possible to indicate an average length of the primary valence chain. If this particular fact is added to your macromolecule, then the two terms become identical, as far as I can see” (quoted from Priesner 1980, 93-4).
What was known as Staudinger’s viscosity law postulated “a quantitative link between viscosity and molecular weight” (Mark 1940, 262), “linear dependency of viscosity on molecular weight” (Meyer and Mark 1930, 178), “proportionality between viscosity and molecular length” (ibid.). “However, if one tries to calculate chain length […] from the viscosity of natural high polymer substances using the formula developed by Staudinger on the basis of this assumption, levels of several µ are the result. This is not easy to reconcile with X-ray analysis and the other physical properties” (ibid.). Mark 1940, 293-294 concluded that “the Staudinger relationship […] only applies with moderate accuracy” and that it was not possible to talk about an “exact law”: “According to Wo[fgang, editor’s note] Ostwald (1883-1943, editor’s note), the Staudinger formula only has the significance of a tangent on arbitrary, for example, s-shaped curves, which represent the real viscosity – molecular weight function” (ibid., 297). Mark’s judgement is quite sympathetic even so: “All in all, the Staudinger relationship represents an approximation for estimation of molecular weights that is viable in many cases, simple and therefore valuable. It does not, however, allow any dependable conclusions to be drawn about molecular details” (ibid., 299).
Staudinger was of the opinion that his viscosity law stood and fell with the assumption “that the threadlike molecules in solution were long, rigid sticks, which were the reason for the high viscosity of the solutions because they obstructed each other mutually in the course of their movements” (Mark 1940, 294): “If these huge molecules are not sticks or rigid chains, how do you explain the high viscosity? […] If you dissolve cotton or silk or rubber, what do you get? A viscous liquid! And why is it viscous? Because the individual molecules are rigid. […] Like sticks. Like tree trunks that are thrown into a river. The tree trunks make it difficult for the water to flow” (Andics 1982, 82). Mark’s objection was “that it is not even possible to assume such exceptionally long, rigid, thread-like particles in view of the numerous findings about the inner mobility of molecules” (Mark 1940, 295): “The claim that the dissolved thread-like molecules are rigid is […] contrary to all the findings about the structure and behaviour of molecules. W[erner, editor’s note] Kuhn (1899-1963, editor’s note) in particular has tried in a very interesting way to describe the form of long chain molecules on the basis of approximately free rotatability and concludes that they are loose bundles with longitudinal and transverse dimensions” (ibid., 296). Staudinger generalised the morphology of macromolecules and did not as a result do justice to the large variety of different physical properties of high polymers that had led – for example – to the distinction between Duroplast, thermoplastics and elastomers: “If rigid chains, sticks are involved, how do you explain the elasticity of the material? (Andics 1982, 83). Mark explained the elasticity of rubber as follows:
“The molecular chains are linked irregularly – like numerous intertwined boiled spaghetti noodles. It is this irregular or amorphous structure that gives rubber and similar substances their elasticity. Stretching rubber changes its molecular structure so much that its physical properties are transformed. The intertwined threads disentangle and form uniform parallel bundles. The molecule no longer has the irregular structure of the flexible and elastic substances; it now has the regular atomic arrangements of crystalline solids […]. And it develops toughness and stiffness that the crystal structure gives the solids” (Mark 197, 127).
It is very important to note that it is not contrary to Staudinger’s macromolecule concept to add network and spatial polymers to the chain polymers, because the “transverse bonds” between the primary valence chains also presented themselves as “primary valent” (Meyer, Mark and van der Wyk 1950, 2). In view of this, Hermann Mark liaised with the Dutch physical chemist Roelof Houwink (1869-1945) to continue empirical development of Staudinger’s viscosity formula into the Mark-Houwink formula (Deichmann 2001, 410).
Staudinger experienced a fiasco at the 1st Faraday Society Meeting, which was held in Cambridge, England, from 26.-28. September 1935 and which Mark also attended:
“I recall that [...] he (= Staudinger, editor’s note) showed such sticks, broke one, and said, ‘If molecules are degraded, their strength is reduced and the viscosity drops dramatically.‘ Then, turning to E[ric, editor’s note] K[eightley, editor’s note] Rideal (1890-1974, editor’s note), who was in the chair, he said, ‘Professor Rideal, what I just said – isn’t it clear?‘ Rideal looked at the broken sticks and said calmly, ‘Yes, I think it is perfectly clear, but wrong.‘ That terminated any further discussion of the point“ (Mark 1993, 82).
However, Staudinger continued to claim obstinately that all macromolecules were rigid, stick-like structures. He was just as unwilling to accept any modifications of his law about the relationship between molecular size and viscosity: “He still adhered to his concept in the 1950s” (Deichmann 2001, 150; cf. ibid., 254). So Hermann Mark continued to make him see red: “Mark once sent Staudinger a gift of one of his books. It was returned, marked ‘unopened’. And Herbert Morawetz recalls that when visiting Professor Staudinger’s widow, he saw another of Mark’s books flagged with a note in the Professor’s handwriting stating, ‘not science, propaganda’” (Mark 1993, XXIV). Staudinger must therefore have been thoroughly astonished by Mark’s invitation to him to give lectures in the United States in 1957 and 1961 as well as by how obligingly he was treated by his host (Mark 1993, XXIV and Deichmann 2001, 186). Back in Germany, however, he was unable to resist making the barbed comment “Mark now believes in macromolecules!” (Mark 1993, 122) – Mark already “believed” in them in 1926! – and thus confirmed involuntarily that he had always erroneously seen Mark as an adversary.
Plenty of recognition for his achievements as a scientist
Mark continued to work unstintingly and indefatigably, also as a dedicated organiser and mastermind in the scientific and industrial communities at both national and international level. Here are a few highlights:
In 1956, the American Academy of Arts and Sciences admitted him as a member.
In 1961, he became dean of the Polytechnic Institute of Brooklyn.
In 1963, he was elected to the National Academy of Science of the United States (anonymous 1980, 277).
From 1946 to 1964, he was Director of the Polymer Research Institute in Brooklyn.
After his retirement as a professor in 1965, he became patron of the Austrian Plastics Institute (Reiter 2017, 416) and completed his book “Giant Molecules”, which appeared in German in 1970.
In 1975, on the occasion of his 80th birthday, the Herman F. Mark Chair of Polymer Sciences was established at the Polytechnic Institute in Brooklyn. The Austrian Research Institute of Chemistry and Technology (OFI) introduced the Hermann F. Mark Medal – an award that has since then been presented every year to prominent representatives of polymer science and the plastics industry.
In 1978, Mark presented the ten-part television programme “Life is all about chemistry“, which was written by the Austrian journalist and scriptwriter Hellmut Andics (1922-1998) and was produced by Österreichischer Rundfunk (ORF).
On 14. January 1980, he was presented the National Medal of Science by US President Jimmy Carter: “The award was made in recognition of a lifetime of contributions to the development of polymer science. I was very gratified by this award, not so much for myself, but for the recognition that polymer science has now in the mainstream of chemistry“ (Mark 1993, 121). A comment that mirrored the spirit of the lecture he had held 43 years before in Vienna (“Chemistry as the groundbreaker for progress”):
“It is not tremendous attention-grabbing individual accomplishments by particularly outstanding chemical research scientists that drive progress; it is instead the painstaking theoretical and practical work done by many diligent people that in its entirety enables substances to be exploited more and more intensively and slowly but surely strengthens our control of these materials. Tribute is therefore due not only to the small number of major representatives of our science, who boldly pave the way for progress and write an unfading entry in the book about the development of mankind, but also to the large number of faithful soldiers, each of whom only adds one small stone to the vast mosaic but all of whom together contribute to a remarkable achievement, that is to say the unstoppable, systematic promotion and optimisation of control over force and matter” (Mark 1993, 371).
Hermann Mark died on 6. April 1992, a month before his 97th birthday, in the house of his son Hans in Austin/Texas. His ashes were buried in Matzleinsdörfer Cemetery in Vienna, right next to his wife, who died in 1970 (Mark 1993, XXIII). Final confirmation of his attachment to the city he was born in – which responded by naming a street after him – Hermann-Mark-Gasse – in the 10th district (Favoriten, Rothneusiedl) in 2009.
Mark’s life can be divided up into two different parts: “Hermann Franz (1895-1938) + Herman Francis (1938-1992) = H. F. Mark (1895-1992)” (Jaenicke 2006, 176), which, however, combined to form a whole again when looked back on in old age: “I have had the good fortune to participate in many areas of science for almost an entire century. It has been an amazing experience; our century has seen astounding intellectual progress …”, Mark announced on his 95th birthday (Mark 1993, XXII). For posterity, he remains alive as the “pioneer of macromolecular chemistry” (Priesner 1980, 53), as the “pioneer in applying modern physics to chemistry” (Mark 1993, XXII), as “… the ‘founding father’ of polymer science and technology” (ibid.). For Deichmann 2001, 185, “Hermann Mark’s success” is […] “unique with respect to the impact that a single German or Austrian emigrant had”.
The following warning from 1982, which is more topical today than ever before, can be considered to be Mark’s message to mankind:
“There is a balance on earth between the plants, which are sun-driven chemical factories, and the animals, which are combustion engines. The plants take CO2 out of the atmosphere and release oxygen, while the animals take oxygen out of the atmosphere and release CO2 […] and a certain balance has developed between these things in the course of three or four hundred million years on the earth. The current mass use of fossil fuels […], i.e. of CO2-generating materials for heat, for transport, for cars, for electricity – basically for everything – is now increasing the CO2 content of the atmosphere noticeably. And this is having the same consequences as the fluorinated hydrocarbons escaping from spray cans: solar radiation is being filtered, because CO2, like fluorinated hydrocarbon, absorbs some sunlight. […] This would lead either to an ice age or to desertification (= greenhouse effect, editor’s note) throughout the earth. […] The terrible thing is that we really are living on a volcano. If the average temperature on earth increases or decreases by only one or two degrees, it’s all over” (Kreuzer 1982, 61.-62).
Milestones in Hermann Mark’s life
8. May 1895: Birth in Vienna
1900-1913: School education; “Abitur“ at Theresianum Academy in Vienna
1913: Voluntary year in the Austro-Hungarian Army
1914-1918: 45 months as a soldier, some of the time as an officer in the Imperial-Royal Rifle Regiment No. II of the Austro-Hungarian Army in Bolzano (mountain infantry); start of chemistry studies at Vienna University
July 1921: Doctorate at Vienna University (doctoral advisor: Wilhelm Schlenk)
1921-1922: Assistant at the Chemical Institute of Friedrich Wilhelms University in Berlin
1922-1927: Member of the scientific staff and, from 1925 onwards, departmental manager at the Kaiser Wilhelm Institute for Fibre Chemistry in Berlin-Dahlem
1925: Qualification to become a professor at Friedrich Wilhelms University in Berlin
1927-1932: Central I. G. Farben laboratory at BASF in Ludwigshafen; adjunct professor of physical chemistry at Karlsruhe Technical University
1932-1938: Full professor of physical chemistry at Vienna University; consultant for I. G. Farben
1938-1940: Head of the research laboratory at Canadian International Pulp and Paper Mill (CIP) in Hawkesbury/Ontario (Canada)
1940 ff.: Technical consultant for the chemical company Du Pont in Wilmington/Delaware (USA)
1940-1965: Adjunct professor and, as of 1942, full professor of organic chemistry at the Polytechnic Institute of Brooklyn and the Polymer Research Institute of Brooklyn in New York City; 1965: retirement
1979: Awarded the National Medal of Science (USA), presentation in the White House in Washington on 14. January 1980