Replacement Products

Rubber

Natural rubber is an elastic hydrocarbon polymer that naturally occurs as a milky colloidal suspension, or latex, in the sap of some plants. The major source of natural rubber is/was from rubber trees. It is used extensively in many applications and products, such as car tyres, hoses, erasers, textiles and gloves. It has many useful properties due to its unique nature as an elastomer and a thermoplastic in addition to the ability for rubber to be vulcanised.

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Original Source

Until the 1940s rubber had been obtained from plantations of rubber tees in tropical areas. In it's pure form, it has limited usefulness. However, with sulfur cross-chain additives its hardness increased and made it less susceptible to chemical attack. Its demand in the automotive industry increased drastically with these changes. Worldwide natural rubber was very limited and by the mid-1942 most of the rubber-producing regions were under Japanese control. Military trucks needed rubber for their tires,and rubber was used in almost every other war machine. The U.S. government launched a major (and largely secret) effort to develop and refine synthetic rubber.

Replacement Material

Synthetic Rubber (styrene-butadiene rubber)
As rubber is a hydrocarbon polymer, research centred around finding a substitute via petroleum refining. Styrene and butadiene are both by-products of petroleum refining and thus are readily obtainable.

Advantages
  • Styrene-butadiene rubber is less likely to deteriorate.
  • It can be vulcanised.
  • It's an important synthetic rubber and is used to manufacture car tires.
  • There are a variety of monomers available such as styrene-butadiene and chloroprene. Advantages in this lie in the variety of physical properties achieved due to small changes in the chemical structures and maintaining the basic desirable properties of rubber.
  • After the war, natural rubber plantations no longer had a stranglehold on rubber supplies, particularly after chemists learned to synthesise isoprene.

Ammonia

Humans use nitrates and ammonium as a fertiliser for crops to increase their yield dramatically, making them extremely important resources for the fast and efficient production of crops. The main natural sources of ammonium and nitrates are in guano (deposits of sun-baked bird droppings) and saltpetre deposits underground. These resources, however, are being depleted much faster than they are being naturally produced.

The world resources of nitrates and ammonium declined steadily until the Haber process was developed. This process was able to synthesise ammonia gas from nitrogen and oxygen in the presence of a magnetite catalyst in an exothermic reaction, which can then be used to produce nitrates. This meant that many countries, particularly Germany, where the Haber process was developed, no longer had to rely on saltpetre or guano imported from Chile for the manufacture of nitrate fertilisers (or explosives). This became important during World War I when the Allies blocked Germany's access to imported ammonia, allowing them continued access to this valuable resource and thus prolonging World War I. Today, the Haber process continues to be an important industrial process for the production of ammonia. About 85% of the world's ammonia resources are produced by the Haber process, and without synthetic fertilisers, the world could not maintain the intensive farming practices required to produce sufficient food to sustain the rapidly growing world population.