Polymer, Berzelius

The word "polymer" (first proposed by Berzelius in 1833) is made of "poly" from the ancient Greek word "mlvq" meaning "many" and "pepot " meaning "part". Polymers are molecules built up from numerous identical chemical "units" spatially repeated to form a chain. From the early times and still nowadays, a distinction is often made between "natural" and "synthetic" polymers, but it is somewhat artificial as natural polymers can now sometimes be synthesized (e.g., synthetic "natural rubber") and some synthetic polymers, which are never found in nature, can be synthesized by natural ways (enzymatic syntheses). 

The word, polymer, was introduced a century before in 1833 by Jons Jacob Berzelius in his famous book, the "Jahres-Bericht". He recognized the fact that two compounds may have the same composition yet differ in molecular weight. Thus, he classified this polymerism as a special type of isomerism. In order to prevent confusion, it should be pointed out that Berzelius had in mind a series of compound related to each other as acetylene C2H2, benzene CgHg, and styrene CgHg are related. 

As a result of the work of early pioneers like Berzelius and Kekule reports on studies of materials we now recognize as high molecular weight, the natural polymers as well as those inadvertent tars from work performed in the pursuit of other goals, frequently used the term, polymer. 

Tartaric acid-glycerol polyesters were reported in 1847 by Berzelius [13] and those of ethylene glycol and succinic acid were reported by Lorenzo in 1863 [14]. Carothers and Van Natta [15] extended much of the earlier work and helped clarify the understanding of the polyesterification reaction in light of the knowledge of polymer chemistry at their time. Polyethylene terephthalate [16, 17] and the polyadipates [18] (for polyurethane resins) were the first major commercial application of polyesters. 

Jince the time of Berzelius, chemists have proposed structures for the amorphous, black substance known as humic acid. In the past 150 years, much experimental work has appeared on the nature of humic acid, most of it based on classical chemical and microbiological studies. Very little information about the molecular structure of humic add has resulted from these studies however. Some of the problems plaguing investigators in this field have been (a) variation in the source of humic acid, (b) variation in the definition of humic fractions of soil and coal, (c) lack of crystallinity of the samples, (d) uncertainty of molecular weight measurements, (e) variation in extraction techniques, and (f) variation in elemental composition. The little unambiguous information that exists today is based on extensive degradation of the humic acid polymer and represents only a small fraction of the total molecule. 

The term polymer was introduced by Berzelius in 1833. These are materials comprised of huge molecules that have very high molecular weight, and are composed of a large number of repeating units named mers. A proper comprehension of the structure of polymers did not come into view until the second decade of the twentieth century. Previously, these compounds were considered... 

Berzelius coins the term polymer for any compound with a molecular weight that is a multiple of the MW of another compound with the same composition... 

Polymers, which received their name from Berzelius in 1833, are macromolecules which have many mer units or parts. Each mer unit (A) may have several functional groups but it is repeated n times to form the poisoner. 

The formation of alkyd resins is a typical example of condensation polymerization. In 1847, Berzelius reported a resinous product formed by the reaction of tartaric acid and glycerol. In 1901, Watson Smith (England) prepared a brittle resinous polymer by... 

Catalysis refers to the phenomenon by which the rate of a chemical reaction is accelerated by a substance (the catalyst) not appreciably consumed in the process. The term catalysis was coined by Berzelius in 1835 and scientifically defined by Ostwald in 1895, but applications based on catalysis can be traced back to thousands of years ago with the discovery of fermentation to produce wine and beer. Nowadays, catalysts are used in 80% of all chemical industrial processes, and create annual global sales of about 1500 billion dollars and contribute directly or indirectly to approximately 35% of the world s GDP. Catalysis is central to a myriad of applications, including the manufacture of commodity, fine, specialty, petro-, and agro- chemicals as well as the production of pharmaceuticals, cosmetics, foods, and polymers. Catalysis is also an important component in new processes for the generation of clean energy, and in the protection of the environment both by abating environmental pollutants and by providing alternative cleaner chemical synthetic procedures. 

A polymer molecule is defined as a molecule of relatively high molecular weight consisting of regularly repeating units, or chemically similar units, connected by primary covalent bonds. The word polymer was coined by the Swedish chemist Berzelius in 1833. It is derived from two Greek roots, poly which means many and meros which implies parts . 

In early discovery of polymers, of course there were a lot of arguments on the basics of polymer science and unclear concepts and terms. Carothers criticized Berzelius [10,13] about his misleading concept on polymers as the term polymers indicated the presence of the same atoms in the same proportions. Carothers described a condensation that requires as starting materials compounds in which at least two functional groups are present in the same molecule (e.g., hydroxy acids, HO-R-COOH, might lead to polyesters, HO[RCOO] RCO- and amino acids to polyamides, NH2[RCONH]j,RCO-.) [10]. In addition, he... 

Thomas Hancock built a factory for producing rubber articles in 1820 and Charles Macintosh obtained waterproof fabric by making a rubber-cloth sandwich in 1823. It is of interest to note that John Jacob BerzeUus coined the word polymer in 1833 just seven years after Michael Faraday had shown rubber to have the composition of CgHg and six years before the discovery of the vulcanization process by Charles Goodyear. Berzelius also coined the terms isomer, catalyst and protein (4) and synthesized glycerly tartrate polyester resins (5). 

The polymerization of styrene and acrylic acid was observed in 1872 but the polymers of these monomers were not produced commercially until the early part of the twentieth century. Likewise, Gay-Lussac and Pelouze in 1833, Berzelius in 1847, Bemmelen in 1856, Lourenco in 1863 and Watson Smith in 1899 investigated the formation of polyesters but these pol3nners were not commercialized until the early part of the twentieth century. 

Another great service that Berzelius rendered to chemistry was the compilation of an annual review of the literature in the physical sciences. The first volume appeared in 1822, and Berzelius continued to compile the sections on chemistry until his death. The Annual Reports were translated Into German by Wohler, and thereby became widely read. As a result of compiling the reports, Berzelius was in a position to make some important generalisations. He realised that, in the case of some reactions, the presence of another material was necessary for change to occur, although this substance was not altered in the process. He coined the term catalysis for this phenomenon. He also introduced the terms isomerism, allotropy, polymer and protein. 

Berzelius, Jons Jakob (1779-1848) A physician and chemist born in Sweden, Berzelius was secretary of the Royal Swedish Academy of Sciences for thirty years. He is credited with discovering the law of constant proportions for inorganic substances and was the first to distinguish organic from inorganic compounds. He developed a system of chemical symbols and a table of relative atomic weights that are stiU in use. In addition to coining such chemical terms as protein, catalysis, polymer, and isomer, he identified the elements cerium, selenium, silicon, and thorium. 

Our discussions of chemistry to this point have focused primarily on molecules of fairly low molecular mass. In nature, however, we find many substances of very high molecular mass, running into millions of amu. Starch and cellulose abound in plants proteins and nucleic acids are found in both plants and animals. In 1827 Jons Jakob Berzelius coined the word polymer (from the Greek polys, "many," and meros, "parts") to denote molecular substances of high molecular mass formed by the polymerization (joining together) of monomers, molecules with low molecular mass. 

The nomenclature had not been changed yet the lecture notes of Max Brunner (student in the winter semester 1921/22) give a definition of the term polymer that is almost identical with that of Berzelius (Fig. 6). 

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