Anecdotal History of Styrene and Polystyrene

A formal history of styrene and polystyrene from 1839 through 1952 appears in the Styrene monograph edited by Boundy and writer but now out of print. Updating of the story by several teams of Dow writers appeared in the Kirk-Othmer Encyclopedia, the Encyclopedia of Polymer Science and Technology, and the SPE Award address of Amos. We propose a more personalized history written from the perspective of one whose 40-year professional career was involved in scientific and technological aspects of the subject. We view this history as a complex interplay of science, technology, industrial activity, management decisions, legal and patent activities, people, and the vagaries of World War II. Germany had an early industrial lead prior to 1941 with a monomer process and mass polymerization techniques. Original work on styrene-butadiene elastomers was another first. Germany also had a scientific lead as academic scientists such as Staudinger, Kern, Schulz, Jenckel, and Ueberreiter became involved in the chemistry and physics of styrene and polystyrene (PS). Mark was first in industry and then in the university. Several United States companies were active with styrene and PS, also prior to 1941. Involvement of the United States in World War II lead to a government decision to produce SBR. This catapulted styrene into a major synthetic chemical. The lead passed from Germany to the United States, especially with the large excess capacity for monomer after 1945. Management decisions encouraged diverse large-scale polymer uses for styrene, aided by the low price for the monomer. Through a bizarre series of events (war, people, and legal action), proprietary industrial knowledge in both Germany and the United States had diffused into the domain of public knowledge. Styrene and PS now face the problems of any petrochemical product.     

Feedstock recycling of synthetic and natural rubber by pyrolysis in a fluidized bed

An indirect heated fluidized bed process has been used for the pyrolysis of synthetic and natural rubber. The throughput capacity for the continuously running plant was 500–3000 g/h. The results are compared to a pilot plant for the pyrolysis of whole tires. Beside the recovery of oil and carbon black it was another goal of the study to investigate how much monomer material such as isoprene and isobutene can be obtained from synthetic and natural rubber. The pyrolysis parameters were optimized such as pyrolysis temperature, kind of fluidizing gas, and residence time of the gas in the pyrolysis reactor. Main products of the pyrolysis of tires are an aromatic-rich oil and carbon black, which can be reused. While it was possible to obtain only 2–4 wt% of isobutene, the isoprene content reached 22 wt% from natural rubber.     

Kurt Gottlob – ein Leben für den Kautschuk

The chemist Kurt Gottlob (1881–1925) was one of the best‐known rubber technologists of the early 20th century. Kurt Gottlob's contributions were covering nearly all areas of rubber chemistry. Kurt Gottlob was one of the most important and creative members of the team around Fritz Hofmann (1866–1956) at Farbenfabriken, vorm. Friedr. Bayer, which developed methyl rubber, the world's first synthetic rubber. Together with Fritz Hofmann he discovered the organic accelerators, which revolutionized the vulcanization process of rubber. With his polymerization of isoprene in the presence of aqueous colloidal solutions of albumin he applied the principle of emulsion polymerization for the first time.     

Malaria chemotherapy and the "kaleidoscopic" organisation of biomedical research during world war II

The paper describes the organisational and scientific evolution of the US antimalarial program during World War II. This program screened some 14,000 compounds for antimalarial activity, selected atabrine as the drug of choice in 1943, and later identified chloroquine as a superior compound. It became, arguably, the largest biomedical research effort of the first half of the twentieth century, involving chemical and pharmaceutical companies, diverse university researchers, and non-profit and government laboratories. Beyond scientific research, the innovations of the wartime antimalarial program were chiefly in three areas, communication, scale and administration. The program drew on resources - intellectual, material and organisational - created in Germany by researchers at Bayer, and in the US by the Rockefeller Foundation and Institutes. The paper examines the antimalarial program as one of the formative models for later programs such as the National Institutes of Health. This account supports the claim that wartime work was essential to the development of NIH, if only because the confused and faltering structures of the early war years, 1939-1943, do not suggest that all the organisational infrastructure for large scale, multi-centre co-operative research was in place prior to World War II.     

Quantitative analysis of isoprene units in natural rubber and synthetic polyisoprene using 1H-NMR spectroscopy with an internal standard

Isoprene units in natural rubber (NR) and its synthetic analogues were quantified by ¹H-NMR spectroscopy using polyethylene glycol (PEG) as an internal standard. The effect of PEG and rubber concentrations, molar ratio of rubber/PEG, measuring temperature and scan number on the quantification was investigated to establish the respective working range. Analysis of commercial grades of NR revealed that the differences in 1,4 isoprene content is caused by the production process and feedstock, in which proteins and lipids were found to be the major impurity in NR. Gel fraction of NR has insignificant effect on the measurement of 1,4 isoprene content. Furthermore, the new method was found to produce good results for the quantification of 1,4 and 3,4 units of synthetic polyisoprenes.     

Hermann Staudinger und der Kunstpfeffer. Ersatzgewürze

During the First and Second World Wars, Germany could no longer import colonial goods, such as coffee, pepper and other tropical spices. Although these commodities were not essential for the daily caloric requirement of the German people, their absence was felt considerably. Chemists began to search for a lot of appropriate substitutes, which in the end meant an enormous impact on the industry of artificial flavours. When pepper, the most important hot tasting condiment, became rare, Hermann Staudinger, the later Nobel Prize winner in Chemistry, and Paul Immerwahr were anxious to find a process that would allow the large‐scale production of a synthetic pepper‐substitute by a method easier and cheaper than the one based on synthetic piperine. Staudinger's pepper‐substitute was produced by the Chemische Fabrik Dr. Höhn & Co. in Neuss on the Rhine during the First World War and by the Hoechst plant of I.G. Farben and C.F. Boehringer Mannheim during the Second World War.     

Ein synthetisches Kaffeearoma

Initiated by the experiences of World War I Hermann Staudinger tried to create a synthetic coffee flavor and asked his assistant Tadeusz Reichstein first with the isolation and analysis of the natural flavor followed by the development of a synthetic substitute. Reichstein worked from 1922 until 1932 to solve this task which proved to be very intricate. Since 1928 he worked closely together with Max Kerschbaum from “Haarman and Reimer”, then the leading company for artificial flavors. They finished their research without being able to create with their “Coffarom” a real substitute for the natural coffee flavor. Nevertheless this project is of significant interest for the history of chemistry because of the highly sophisticated microchemical methods applied as well as it is interesting as an early example of the cooperation between university‐based scientific research and industry‐sponsored applied chemistry. When Max Morgenthaler, working for the Nestlé company developed his “Nescafé”, the ascent of this firm to the biggest food producing conglomerate in the world began.     

One hundred years of the Fritz Haber Institute

We outline the institutional history and highlight aspects of the scientific history of the Fritz Haber Institute (FHI) of the Max Planck Society, successor to the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry, from its founding in 1911 until about the turn of the 21st century. Established as one of the first two Kaiser Wilhelm Institutes, the Institute began as a much-awaited remedy for what prominent German chemists warned was the waning of Germany's scientific and technological superiority relative to the United States and to other European nations. The history of the Institute has largely paralleled that of 20th century Germany. It spearheaded the research and development of chemical weapons during World War I, then experienced a "golden era" during the 1920s and early 1930s, in spite of financial hardships. Under the National Socialists it suffered a purge of its scientific staff and a diversion of its research into the service of the new regime, accompanied by a breakdown in its international relations. In the immediate aftermath of World War II it suffered crippling material losses, from which it recovered slowly in the postwar era. In 1952, the Institute took the name of its founding director and the following year joined the fledgling Max Planck Society, successor to the Kaiser Wilhelm Society. During the 1950s and 1960s, the Institute supported diverse research into the structure of matter and electron microscopy in its geographically isolated and politically precarious location in West Berlin. In subsequent decades, as Berlin benefited from the policies of détente and later glasnost and the Max Planck Society continued to reassess its preferred model of a research institute, the FHI reorganized around a board of coequal scientific directors and renewed its focus on the investigation of elementary processes on surfaces and interfaces, topics of research that had been central to the work of Fritz Haber and the first "golden era" of the Institute. Throughout its one-hundred-year history, the Institute's pace-setting research has been shaped by dozens of distinguished scientists, among them seven Nobel laureates. Here we highlight the contributions made at the Institute to the fields of gas-phase kinetics and dynamics, early quantum physics, colloid chemistry, electron microscopy, and surface chemistry, and we give an account of the key role the Institute played in implementing the Berlin Electron Synchrotron (BESSY I and II). Current research at the Institute in surface science and catalysis as well as molecular physics and spectroscopy is exemplified in this issue [Angew. Chem. 2011, 123, 10242; Angew. Chem. Int. Ed. 2011, 50, 10064].     

Structural and mechanical study of elastomers under plane deformation

The plane shrinkage of various elastomers [natural rubber, synthetic isoprene rubber, and plasticized poly(vinyl chloride)] at room temperature has been studied via direct microscopic observations. Prior to deformation, the surface of polymer samples is decorated with a thin (several nanometers) metallic layer. Further deformation leads to formation of the surface relief in the coating. An analysis of the formed microreliefs allows one to visualize and characterize the induced stress field in the sample. The shrinkage of poly(vinyl chloride) samples is accompanied by development of the uniform surface relief over the whole surface of the deformed polymer. This fact suggests a homogeneous character of the stress field and, hence, a homogeneous structure of the polymer sample. In the case of crosslinked rubbers (natural rubber and synthetic isoprene rubber), their plane shrinkage leads to the development of an irregular pattern on the polymer surface. In addition to the folded surface relief that is typical of the poly(vinyl chloride) structure, one can observe 20-to 50-μm “islands,” which are characterized by their own morphological features. Information on structural inhomogeneity of rubbers that is obtained by scanning electron microscopy correlates with the data of DSC measurements. The advantages of electron microscopic procedure for studying structural rearrangements in polymers during strain recovery of elastomers are demonstrated.     

Influence of the structure of organic peroxides on the efficiency of modification of SKI-3 rubber with dicarboxylic acid anhydrides in solution

The efficiency of modification of synthetic isoprene rubber with maleic and endic anhydrides in solution was examined as influenced by a number of initiator systems: dicumyl, dibenzoyl, and dilauroyl peroxides.     

Chasing molecules that were never there: misassigned natural products and the role of chemical synthesis in modern structure elucidation

Over the course of the past half century, the structural elucidation of unknown natural products has undergone a tremendous revolution. Before World War II, a chemist would have relied almost exclusively on the art of chemical synthesis, primarily in the form of degradation and derivatization reactions, to develop and test structural hypotheses in a process that often took years to complete when grams of material were available. Today, a battery of advanced spectroscopic methods, such as multidimensional NMR spectroscopy and high-resolution mass spectrometry, not to mention X-ray crystallography, exist for the expeditious assignment of structures to highly complex molecules isolated from nature in milligram or sub-milligram quantities. In fact, it could be argued that the characterization of natural products has become a routine task, one which no longer even requires a reaction flask! This Review makes the case that imaginative detective work and chemical synthesis still have important roles to play in the process of solving nature's most intriguing molecular puzzles.     

Studies on the Morphology of Natural Rubber/Polyacrylate Interpenetrating Polymer Networks

The interpenetrating polymer network(IPN) systems have attracted a lot of attention because of their unique two-phase structure and properties. There have been many publications concerning the IPNs in which poly (isoprene) (PIP) or polyacrylates (PAC) is formed as one of the networks.In the present study, Four serles of natural rubber(NR)/PAC IPNs were prepared and their morphologies were investigated with dynamic mechanics analysis(DMA) and transmission electron microscopy (TEM).     

The chemical effects of photo-oxidation on isoprene rubber

There has been a detailed study of the non-volatile products of the photo-oxidation of two kinds of cis-1,4-polyisoprene, viz. natural and synthetic (98% cis), by irradiating films in the solid state under ambient conditions. I. R., ¹H- and ¹³C-NMR and chemical methods indicated the formation of the following functional groups: hydroperoxides, alcohols, ketones, aldehydes, epoxides and carboxylic acids. There is also evidence for the formation of esters and ethers. Viscometric measurements showed that chain-scission predominates over cross-linking for irradiation of toluene solutions of the rubbers. Photo-oxidation kinetic measurements for films containing singlet oxygen quenchers, such as 1,2-diazabicyclo[2,2,2]octane and diphenyl-p-isobenzofuran, showed that singlet oxygen is not responsible for the initiation of the environmental photo-oxidation of cis-1,4-polyisoprene. Increasing the number of successive coagulation steps, in the purification of natural rubber, decreased its stability, confirming the presence of an intrinsic natural stabilizer. Synthetic isoprene rubber showed less stability than natural rubber.     

Effect of Arylamines Containing 3,5-Di-tert-butyl-4-hydroxyphenyl Fragment on Stability of Polypropylene,Isoprene Rubber,and Thermoelastoplastics Derived from Them

The effect of arylamines containing a sterically hindered phenolic fragment on the resistance of polypropylene, synthetic isoprene rubber, and thermoelastoplastics derived from them to oxidative and thermomechanical degradation was studied in relation to the structure of the additives.     

The Legacy and Future of Radioactive Waste Management at the Millennium

Wastes containing radioactive materials have been produced ever since ore recovery and processing began; however, such materials did not become of public concern until the large-scale activities involving uranium and thorium ores and nuclear fission during and after World War II. Efforts to provide disposal sites for radioactive wastes, especially those associated with nuclear weapons and nuclear energy, have been largely unsuccessful for the past 40 years or so and are nearing crisis proportions as the new millennium begins — its eventual resolution is believed to require greater reliance on stewardship and a larger governmental presence.     

Determination of kinetic constants of the cationic copolymerization of isobutylene with isoprene

A theoretical kinetic model has been developed for cationic isobutylene–isoprene copolymerization in methyl chloride with an AlCl₃ catalyst. Kinetic constants of this process have been derived from experimental data available on copolymerization kinetics (isobutylene conversion curve) and on molecular weight characteristics of the isobutylene–isoprene copolymer (butyl rubber). The adequacy of the theoretical kinetic model of the isobutylene–isoprene copolymerization process has been demonstrated by comparing the calculated molecular weight characteristics and degree of unsaturation of butyl rubber to the corresponding independent experimental data.     

双烯类液体橡胶的研发进展

液体橡胶作为合成橡胶的重要种类,是室温下能流动的橡胶材料。本文介绍了液体橡胶的性能特点及分类,着重阐述了双烯类液体橡胶即液体聚丁二烯橡胶、液体丁腈橡胶、液体异戊橡胶、液体丁苯橡胶和液体氯丁橡胶的结构特征、性能特点及主要用途,并进一步探讨了它们的研发、生产和使用情况。液体橡胶便于实现生产连续化和自动化,且加工方便,顺应时代发展的"低碳"潮流。从产品种类、牌号,应用范围等方面对今后的发展提出了建议。     

A history of atomic absorption spectroscopy

Spectrochemical analysis originated with the work of Kirchoff and Bunsen in 1860 but found relatively little application until the 1930s. Arc-spark emission and, to a lesser extent, flame emission methods then became popular. Following World War II flame emission became very popular. In 1955 the modern era of atomic absorption spectroscopy began with the work of Walsh and Alkemade and Milatz. The time since 1955 can be divided into seven year periods. The first was an induction period (1955–1962) when AA received attention from only a very few people. This was followed by a growth period (1962–1969) when most of what we see today was developed, and then by a period of relative stability (1969–1976) when AA contributed greatly to other fields. We are now in a period of great change, which started in about 1976, due to the impact of computer technology on individual laboratory instruments.     

Metathesis transformations of natural products: cross-metathesis of natural rubber and mandarin oil by Ru-alkylidene catalysts

This study reports on the degradation of natural rubber (NR) via crossmetathesis with mandarin oil and d-limonene, an abundant compound in essential oils; that were used as chain transfer agents (CTAs) and green solvents. Reactions were performed in the presence of the ruthenium-alkylidene catalysts (PCy?)?(Cl)?Ru=CHPh (I) and (1,3-dimesityl-4,5-dihydroimidazol-2-ylidene) (PCy?)Cl?Ru=CHPh (II), respectively. Catalyst II bears an N-heterocyclic carbene ligand (NHC) bounded to the ruthenium atom, which has a strong basic character; therefore it is more active toward trisubstituted olefins in comparison with catalyst I. In both cases, isolated monoterpene-terminated isoprene oligomers were obtained as products of the cross-metathesis degradation of NR. In the presence of catalyst II molecular weight values around M(n) × 102 and yields of 80% were obtained; whereas with catalyst I, the molecular weights of products were about M(n) × 10? with yields ranging 70 to 74%. The composition and yield of NR degradation products were determined by GC/MS (EI) analysis and it was found that the oligomers obtained have primarily one vinyl group and one terpene-monocyclic group at the chain end, with isoprene units A(m) = 2, 3 y 4.     

Die Firma Leopold Cassella & Co.

Leopold Cassella & Co. originated in the Frankfurt ghetto as a trading company for natural dyestuffs, and developped into a worldwide acting enterprise by the joint activities of the Cassella‐Gans‐Weinberg families. After the invention of the first synthetic dyes the owner families 1870 founded a chemical and dyestuff factory. Clever exploration and exploitation of the chemistry of naphthaline and its derivatives made the works into the largest and most profitable azo‐dyestuff‐company of the world about 1900. Leopold Cassella & Co. offered their products worldwide thru a network of fully and partly owned, cooperating companies. In 1925 the company joined IG‐Farbenindustrie AG, but remained an own entity, until the Nazi‐government – which brought distress and death to many members of the ownerfamilies – 1938 ordered the full integration (arization) into IG‐Farbenindustrie AG. After the demolition of IG‐Farbenindustrie AG following the end of World War II, Cassella 1952 evolved as an independent dyestuff AG, the majority of which 1970 was bought by Hoechst AG. 1995 Cassella was fully integrated into Hoechst AG, which dissolved itself shortly thereafter. Following a short term with Clariant of Switzerland, the Fechenheim works were sold to private investors, who founded AllessaChemie GmbH, which will celebrate their 10th anniversary on July 1, 2011.