Polymers are the most common and vital concept in Chemistry or chemical science. In our day to day life, we come across many polymers. Few are known to us and few are unknown. Polymers made naturally and also artificially that are prepared in laboratories. In this article, we will learn about polymers, its various other classification and applications.
Polymers reside under the organic chemistry branch of Chemical science. Prior to diving into the concept of polymers let us first know precisely what are polymers? Scientifically polymers are defined as a large molecule or a macromolecule which typically is a sequence of many subunits. In Greek, the term polymer refers to many parts. A polymer is synthesized by combining small molecules or substances into a single huge molecule by the chemical reaction. The small molecules that are used in synthesizing a polymer are called monomers.
Classification of polymers
Polymers are a huge chain of molecules. Therefore, cannot be classified under a single branch. Due to their complex structures, different behaviours, and vast applications we can, classify polymers based on the following criteria:
Polymers based on the Source of Availability
Based on the source of availability we can classify the polymers as follows
- Natural Polymers
These polymers are naturally occurring and are generally found in plants and animals.
Example: Proteins, starch, cellulose, and rubber.
- Semi-synthetic Polymers
They are derived from naturally occurring polymers and undergo additional chemical modification.
Example: Cellulose nitrate, cellulose acetate.
- Synthetic Polymers
These are entirely man-made polymers. In the category of synthetic polymers there comes the most widely used product that is plastic. Usually people wonder, is plastic a polymer? Plastic is a polymer that is used extensively.
Example: , Plastic, Nylon-6, 6, polyether etc.
Based on the Structure of the Monomer Chain
Based on the Structure of the Monomer Chain polymers can be classified as follows
- Linear Polymers
The structure of polymers that comprises long and straight chains are called linear polymers.
Example: PVC, i.e. polyvinyl chloride
- Branched-chain Polymers
When linear chains of a polymer form branches, then, such polymers are known as branched-chain polymers.
Example: Low-density polythene.
- Cross-linked Polymers
They are bifunctional and trifunctional monomers. They hold a stronger covalent bond in comparison to other linear polymers.
Example: Bakelite and melamine.
Based on mode of polymerization
Based on the mode of polymerization, polymers are classified as follows
- Addition polymers
Polymers that are formed by the subsequent and repeated addition of monomer molecules possessing either double or triple bonds.
- Condensation polymers
Polymers that are formed by a repeated condensation reaction between the two different tri-functional or bi-functional monomeric units are known as condensation polymers.
Example: Nylon 6, terylene, etc.
Listed below are the applications of polymers
Synthetic polymers uses
- Polypropene: Majorly used in industries such as textiles, packaging, stationery, plastics, aircraft, construction, rope, toys, etc.
- Polystyrene: Actively used in the industry for packing products like bottles, toys, containers, trays, disposable glasses and plates, tv cabinets and lids.
- PVC: The most prominent use of polyvinyl chloride is the manufacture of sewage pipes. It is also used as an insulator in the electric cables. Also used in clothing and some furniture manufacturing units.
- Glyptal: Predominantly used in the manufacture of paints, coatings, and lacquers.
- Bakelite: Used for constructing electrical switches, kitchen products, toys, jewellery, firearms, insulators, computer discs, etc.
Natural polymers uses
- Collagen: It is mainly a protein builder. It builds up the connective tissue present in the skin of homo sapiens.
- Latex- Latex is known to be a variety of rubber, and rubber is a natural polymer.
- Cellulose– Cellulose is one of the purest forms of natural cellulose is cotton. The paper produced from the woods of trees and also the shielding materials in leaves and plants mainly comprise cellulose.
- Starch– Starch is the derivative of condensation polymerization and is a source of carbohydrates.
Polymers are huge molecules with a wide variety of applications. The concept and idea in preparation of polymers is vast and many researchers are examining in knowing deeper about polymers and its properties.