A polymer is a long chain that is made up of repeating, similar links. Polymers are very fascinating large molecules which are composed of several small ones. The word “polymer” comes from the Greek language and means “many parts”. Now-a-days, polymers find use in a variety of applications. If you are thinking that the polythene bag in which you used to bring groceries has something to do with polymers, you are absolutely correct. Polythene is a misnomer of polyethylene, a polymer that is made up of several repeating ethylene units.
What are polymers made of?
Polymers are made up of several smaller units of molecules that are linked and connected together with the help of strong bonds that stay in place. These smaller units are referred to as monomers. A monomer is a single molecule or group of molecules which form the polymer chain. Each monomer unit is covalently bonded to another unit and several of them link together to form a high mass molecule. This high mass in turn allows a polymer to have different physical and, sometimes, chemical attributes than the monomer units that make it up. Many synthetic polymers have been made over the years and polymer chemistry has gained much importance in research as new researchers pursue challenges in this field of chemistry.
How are polymers made?
Polymers are said to be formed by one of the two methods: step-growth and chain growth. These two are the generally applied methods when a polymer is synthesized. In the chain grown methods, the scientists try to link the different monomer units one by one with the main polymer chain. This is the method used to produce polyethylene, which is now being condemned due to its non-biodegradable nature. The second method of making a polymer is the step-growth procedure. If the monomer units are allowed to come into proximity with each other such that they are closer to each other than they are to the polymer chain, then it is possible for them to link together and form smaller polymers. These polymers can then attach themselves to the main polymer chain and form an even bigger chain. The cloth fabric polyester is made in a similar fashion.
Improvements on natural polymers
There are several types of naturally occurring polymers as well and we have been using polymers in one form or other from the dawn of time. Silk, rubber, wood and wool are some of the natural polymers that have been used by the humans for various purposes. Chemists try to find ways to study these naturally occurring polymers and modify them so that these can be improved upon for qualities for which these are most desired. One such example of an improvement is the vulcanized rubber. Natural rubber is a sticky gum which cannot be made use of in its natural form. But it was found out that on heating this resin with sulfur, not only can it be made less sticky but its properties can be vastly improved.