Rubber, history structure

A detailed discussion of the history structure and applications of natural rubber appears in the May 1990 issue of the Journal of Chemical Education... 

As a class, these compounds are related to indigo, which is the oldest of all vat dyes. Indigo itself, during its comparatively short history as a commercial pigment, was used especially in rubber. Its structure was first described in 1883 by A.V. Bayer. Knowledge of this structure, together with the development of an industrial scale synthesis, facilitated the development of a series of indigo-based colorants. 

This substance has a long history.245 Its structure was established by Staudinger on the basis of decomposition products and molecular weight determinations through viscosity.246 A paper on the early development of the Polish rubber industry stresses the difficulties faced in the 19th century, the existence of two factories before 1914, and the rapid growth after 1918.247... 

In the last years of the history shown in Table II we see the announcements of new commercial thermoplastic rubbers. Uniroyal TPR appeared in 1971. (This thermoplastic rubber many not be a block polymer. Presumably it is a blend that achieves its properties by virtue of interpenetrating networks between the plastic and rubber constituents. The exact structure has not been disclosed.) Du Pont s Hytrel, an (A-B) polyetherpolyester thermoplastic rubber, came out in 1972. Also in 1972, Shell announced a second generation block polymer, Kraton-G, which is a three-block S-EB-S thermoplastic rubber (EB represents an ethylene-butylene rubbery midblock). 

The successful scale-up of advancement and modification of rubber-modified epoxy resins is discussed. Mechanisms are proposed for both advancement and esterification reactions as catalyzed by triphenylphosphine which are consistent with experimental results. A plausible mechanism for the destruction of the catalyst is also presented. The morphology of these materials is determined to be core-shell structures, dependent upon composition and reaction and processing conditions. Model studies have been performed to determine the effects of thermal history on the kinetics of reaction. These efforts have resulted in the successful scale-up and use of rubber-modified epoxy resins as functional coatings in the electronics industry. 

Polyurethanes (PUs) are a family of condensation polymers that include the urethane (-NHCOO-) group in the chemical structure (Figure 5.1). The history of PUs started in 1937 when Dr Otto Bayer of Bayer Germany invented the diisocyanate polyaddition process. The early applications of PUs were mainly on soft foams and nonsegmented semicrystalline fibers. The lack of rubber materials during WWII has led to the intensive development of PU elastomers. In 1950, Bayer launched the first PU elastomer product, Vulkollan rubbers. Since then, PU elastomers have been used extensively, particular in medical, textile, automobile, and architecture industries [1-3]. 

The history of polymer science (169,170), takes the reader back to before the macromolecular hypothesis. Natural rubber, civ-polyisoprene, was investigated around the turn of the twentieth century. Morawetz (169) writes of the destructive distillation of rubber to isoprene, and of the ozonolysis of rubber to levulinic aldehyde. These studies led to the dimer ring structure of dimethyl-cyclooctadiene for ds-polyisoprene ... 

The early history of polymers is really the conversion of natural polymers into useful materials. Examples include the vulcanization of rubber (Goodyear, 1839), celluloid (which is plasticized cellulose nitrate—Hyatt, 1868), and cellulose-derived fibres, e.g. cuprammonia rayon (Despeisses, 1890) and viscose rayon (Cross, Bevan and Beadle, 1892). The first truly synthetic polymer, that is, one made from laboratory chemicals, was Bakelite (Bakeland, 1907). This was made from phenol and formaldehyde. Bakeland probably did not know the chemical structure of the Bakelite, but he did realize that organic chemicals containing multiple functionality yielded insoluble materials. The various phenol-formaldehyde resins (PF), e.g. Bakelite and novolacs, were thus obtained in an empirical manner. 

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