Category Chemistry

How can we classify polymers?

          We have a tendency to classify everything around us. Similar things are often grouped together for the ease of understanding. Polymers too can be grouped based on different criteria.

          We already discussed natural, synthetic and semi-synthetic polymers. This classification is based on their source. Are there other possible ways to classify them? Indeed yes!

         Polymers can be clubbed together based on their structure, molecular forces and type of polymerization. Look at the diagram to get a clear picture of this.

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Why is the World War II era a significant period in the history of polymers?

          Polymer production emerged as a strong commercial industry during the Second World War. There was a scar-city of natural materials like rubber and silk during the war years, which created a high demand for them.

          The increasing demand created a crisis which further led to an increase in the production of synthetic substances like nylon and synthetic rubber. Moreover, the scarce natural resources needed to be preserved. This made the synthetic alternatives a priority and plastics made it possible!

          The increase in the production of synthetic polymers touched almost all aspects of daily life. Nylon was used for making parachutes, body armours, ropes and helmet liners. It caused a huge change in the fashion industry as well. Rayon, the new synthetic material discovered in the 1930s solved the crisis in natural fabrics and was widely used to make clothing.

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Who is known as the father of polymer chemistry?

          On account of his contributions to polymer science education and research, Herman Francis Mark is known as the father of polymer chemistry. He worked on polymers for almost 75 years and produced more than 600 research papers and 40 books about polymer chemistry. A huge number indeed!

          Mark studied molecular structures of natural textile fibres like silk and wool. He applied modern physics to the study of large molecules; his work on molecular structures using X-Ray diffraction provided sufficient evidence for macromolecular theory of polymer structure.

         Mark’s interests included the mechanical properties of polymers. He led the commercial production of polystyrene, a tough colourless plastic. He is also credited for developing several theories and even an equation!

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Why is Hermann Staudinger an important figure in polymer chemistry?

          Herman Staudinger was not the first chemist to work with polymers. But his significant contributions laid the foundations to diverse applications of polymers.

          Staudinger was a professor in organic chemistry at Zurich when he proposed some of the pioneering theories on polymer structures of fibres and plastics.

          In the 1920s, he found out that rubber has a high molecular weight. He also presented a paper showing several reactions capable of forming structures high molecular weight.

          Staudinger explained how smaller units combine to form a large structure. He called the process polymerization. Before that, polymers were thought of as aggregates of molecules and this idea was based on Thomas Graham’s work. His studies on biological macro-molecules led to a lot of later discoveries of commercial importance.

          Staudinger’s ideas were criticized heavily by other chemists of his time, but were finally accepted by the 1950s. In 1953, he was awarded the Nobel Prize in chemistry for his contributions in understanding macromolecular chemistry.

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What were some of the pioneering discoveries in polymer chemistry?

           Before chemists formulated the basic idea of polymers, Mexicans knew some ways to use polymers. They knew how to modify rubber. Several substances were added to natural rubber. These additives modified and enhanced its properties and were used to make a range of products like bouncing balls.

          Henri Braconnot’s work is the first modern work associated with polymers. In the 1830s, Braconnot along with the help of some others developed celluloid and cellulose acetate, derivatives of cellulose.

          Later in the 1840s, vulcanization of rubber entered the scene which created a huge change in the industry. It was discovered that adding sulphur to natural rubber will make it stable, flexible and prevent stickiness. This led to the production of many useful products like waterproof articles. Vulcanized rubber is undoubtedly the first commercially successful polymer.

          By the 1880s, artificial fibres entered the scene. Hilaire de Chardonnet started the first artificial fibre plant in 1884. It was based on regenerated cellulose which worked as a substitute for silk. Bakelite, the first synthetic plastic was discovered only after more than twenty years in 1907.

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What is polymer degradation?

          Have you observed PVC pipes that are attached to the water tank? You might have noticed that the pipes exposed to sunlight lose colour after a while. These pipes will also lose their strength and become brittle. PVC pipes lose hydrogen chloride gas when exposed to high temperatures.

          Polymers undergo a change their properties like colour, shape or molecular weight when they are exposed to one or more environmental factors like heat, light or chemicals. This change is known as polymer degradation. It is usually undesirable. However, it is useful in recycling polymer waste. Biodegradable plastics are degraded with the help of microorganisms.

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