what are polymers

What are Polymers

The genetic information carrier of our body which is DNA, is a polymer. But what are polymers? Polymers are a long chain of small units of two or more monomers. Find out more about polymers, their synthesis, characteristics and uses.

Our daily life is surrounded by polymers. They can be natural or synthetic but the thing is they are with us all the time. Now the question arises that what are polymer? The word polymer is derived from a Greek word where poly- means "many"; and meros means "part". Polymers are a long chain of small units of two or more monomers. They can be made up of similar monomers or can be a chain of different monomers. These monomers are linked to each other with a covalent bond. They can form linear structure or a branched structure depending upon the reaction taking place. Example: 1) Natural polymers: Polynucleotides (DNA & RNA), polysaccharides, polypeptides, etc. 2) Synthetic polymers: Synthetic rubber, bakelite, nylon, polystyrene, etc. Polymer Synthesis Polymers can be formed naturally or they can also be synthesized in the laboratory. The synthesis can be classified into three types, laboratory synthesis, biological synthesis and modified natural polymers. Laboratory Synthesis Laboratory synthesis of a polymer can be done in two ways, step growth reaction or condensation polymerization and chain growth reaction or additional polymerization. Chain Growth Reaction (Additional Polymerization) In this reaction, the monomers simply come and attach to the reactive end of the monomers. The addition takes place between the same monomers and they attach one by one. There is no loss of any atom or molecule. Examples of chain growth reaction are polyethene (polythene), polystyrene, neoprene, PVC, etc. Reaction will take place as: Ethene + Ethene → Polyethene Step Growth Reaction (Condensation Polymerization) In this type of reaction two or more, same or different monomers attached to form a polymer. In the process, a small byproduct is released which is usually a water molecule. This process can take place between two monomers, monomers with dimers or may be between dimers with an oligomers. Example of step growth reaction are nylon 66, Dacron, Kevlar etc. Reaction will take place as: Carboxylic group + Amine group → Amide group + Water molecule Biological Synthesis Bio-synthesis of polymers takes place in the presence of enzyme. Like synthesis of DNA is carried out in the presence of DNA polymerase enzyme. Biopolymers are divided into three main types polysaccharides, polypeptides, and polynucleotides. These reactions take place naturally and in the presence of a natural enzyme. Glucose (C6H12O6) is a simple sugar and starch, cellulose and glycogen are the polymers of glucose. These all actively participate in providing energy to the body. Modified Natural Polymers There are many natural polymers which are commercially very useful. These type of natural polymers are synthesis in the laboratory. For example: Natural rubber is heated in the presence of sulfur to form vulcanized rubber. One more example can be reaction of nitric acid with cellulose which forms nitrocellulose. Characteristics of Polymers Polymers make a very distinct position in the world of chemistry. Following are some of the characteristic features of polymers.
  • The physical properties of a polymer depend upon its chain length, side group, cross linking and branching.
  • If the polymer consists of same unit of monomers then it is known as homopolymer and if the chain consists of different monomer units then it is called copolymer.
  • With the increase in the chain length, the boiling point, melting point and viscosity increases and mobility decreases.
  • Cross-linking and the bonds between the monomers decide the compounds tensile strength.
  • There are two types of polymers, thermoplastics and thermosetting. Thermoplastics can be molded and can be reused but thermosettings are the polymers which do not mold and can never be reused.
  • Because of their crystalline structure they are strong and are not easily breakable.
  • They can be easily colored hence you can see its products in different colors and shades.
What are Polymers Used for? Polymers can be used in various sectors of life. Following are some of the applications of a polymers which will help you to knows its importance and its usage in everyday life.
  • It is very useful in the industrial sector for making automobile parts, pipes, tanks, matrix for composites, nylon ropes, packing materials, insulation, wood substitutes, elastomeresives, etc.
  • Plastic containers of many shape and size are available in the market which are light weight and are quite inexpensive.
  • There are many polymeric products available in the market which help the soil to become aerated and promotes the growth of the plant.
  • Polymers are used in the medical purposes also. They are useful in the replacement of the heart valves and blood vessels. Dacron, polyurethane and teflon are used for this purpose.
  • Polymer is very well-known in the sports world. They are used in playground equipment, protective helmets, dress fabrics, various balls, basketball & football net, golf clubs, swimming pools, etc
  • It is also used while taking protective measures like firefighters jacket, driving suits, flights suits, thermal blankets, etc.
Polymers have some disadvantages too like the invention of plastic. It is very useful but at the same time, it is very harmful to the nature and environment. But this can be overcome by the plastic recycling methods. I hope you would have gathered lots of information about polymers and would have understood the importance of it in our daily life.

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