Natural rubber history

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

The rubber industry has a long and colorful history. Natural rubber is produced from latex, a milky fluid found in cells that lie between the bark and the wood of many plants. You may have seen latex flow from the broken stalks of milkweed plants, but the source of commercial rubber is the Hevea tree, a native of Brazil. When the bark of this tree is slashed, its milky white sap oozes out and can be collected in cups mounted on the tree s trunk. The people of the Amazon jungle made bouncing balls, shoes, and water Jars out of rubber, and Portuguese explorers sent waterproof boots and a rubber-coated coat back to their king. The first commercial exports included some rubber shoes shipped to Boston in 1823. 

Hevea rubber is undoubtedly one of the unique crops of history and of all agriculture, and one of the most interesting. It is not easy to produce rubber. Research is the tool by which it is possible to grow vast acreages of the tree as a profitable crop. This could never have been done without the past /and present intensive investigations of careful scientists over more than 30 years. Repeated reference in the literature indicates that diseases are the limiting factors in natural rubber production, and that planters owe a debt to disease-control workers. 

Latex sensitivity Administer with caution to patients with a possible history of latex sensitivity packaging may contain dry natural rubber. 

FGD Absorber case histories confirm that the chlorobutyl linings give trouble free service when correctly applied and cured. Chlorobutyl linings offer excellent chemical, heat, weather and ozone resistance compared to natural rubber. 

Polymer technology is quite old compared to polymer science. For example, natural rubber was first masticated to render it suitable for dissolution or spreading on cloth in 1820. and the first patents on vulcanization appeared some twenty years later. About another one hundred years were to elapse, however, before it was generally accepted that natural rubber and other polymers are composed of giant covalently bonded molecules that differ from ordinary molecules primarily only in size. (The historical development of modern ideas of polymer constitution is traced by Flory in his classical book on polymer chemistry [ I ], while Brydson [2] reviews the history of polymer technology.) Since some of the terms we are going to review derive from technology, they are less precisely defined than those the... 

History of Natural Rubber, Parts 3 and 4, e-publication, http //www.irrdb.com/IRRDB/NaturalRubber/History/History3.htm and http //www.irrdb.com/IRRDB/NaturalRubber/History/History4.htm. 

Within the specific context of this chapter, renewable resources represent the obvious answer to the quest for macromolecular materials capable of replacing their fossil-based counterparts [2, 3]. This is not as original as it sounds, because, apart from the role of natural polymers throughout our history evoked above, the very first synthetic polymer commodities, developed during the second half of the nineteenth century, namely cellulose esters, vulcanized natural rubber, rosin derivatives, terpene resins , were all derived from renewable resources. What is new and particularly promising, has to do with the growing momentum that this... 

The development of plastics also reflects economic history. Restrictions on imported latex, wool, silk and other natural materials to Europe during the Second World War resulted in the rapid development of alternative synthetic plastics. Table 1 shows that between 1935 and 1945, many new polymers were introduced including polyethylene, polyamides, poly(methyl methacrylate), polyurethanes, poly(vinyl chloride) (PVC), silicones, epoxies, polytetrafluoro-ethylene and polystyrene. Polyethylene was incorporated into radar systems while PVC replaced the limited stocks of natural rubber as cable insulation. 

Rubber is one of the few examples where chemical synthesis succeeded in a nearly identical performance copy of a natural polymer (polyisoprene) - albeit with a completely different chemical composition (styrene-butadiene-rubber, SBR). Regarding sustainable development, the complete imbalance of the early rubber history has emanated during recent years into equilibrium between natural and synthetic rubber. 

In view of the long history of research efforts on filled rubbers, it is not surprising that the initial works on filled polymer blends appeared in publications authored by rubber compounders and carbon black vendors [17, 18]. For instance, Walters and Keyte [17] observed that the compound ingredients, such as CB and zinc oxide, were not homogenously dispersed in rubber blends. Hess et al. [18] also reported a series of fundamental observations. First, they observed that filler particles tend to remain in the lower viscosity phase, in the absence of significant filler-matrix interactions. However, in the presence of strong polar-polar interactions between the filler particles and one of the phases, the particles were found to be selectively dispersed in the more polar phase and the viscosity became less important. More recently. Portal et al. [19] also presented similar observations about selective localization of CB particles in the natural rubber (NR) phase in NR/ polybutadiene blends. 

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