Polymers

What are Polymers?

A substance or a material consisting of very large molecules or macromolecules composed of many repeating subunits is known as polymer. Due to their broad spectrum, both natural and synthetic polymers play essential roles in our everyday life. Polymers belong to the family of synthetic plastic such as polystyrene to natural polymers to natural biopolymers such as protein and DNA that are fundamental to biological structure and function. Polymers synthetic and natural both are created by polymerization of many small molecules named as monomers. Their large molecular mass relative to small molecule compounds produces unique physical properties.

[Image to be added Soon]

Polymer term is derived from the Greek word polus meaning many or much and meros meaning parts, and refers to the large molecules whose structure is composed of many repeating units, from which originates a characteristic of higher relative molecules whose structure composes of multiple properties in it. Polymer drive composing this unit actually or conceptually from molecules of low relative molecular mass. In 1833 the term was coined by Jons Jacob Berzelius, though with a definition distinct from the modern IUPAC definition. 

History

Essential components of commodities are said to be for polymers since the early day for humankind. The use of linen fibers, cotton, wool for garments, paper reeds for paper are just a few examples of how our ancestors exploited polymers containing raw material to obtain artifacts. The cactus trees latex sap reached Europe in the 16th century from South America long after olmec, atzec and maya had started using it as a material to make balls and waterproof textiles and containers. The polymers chemical manipulation dates back to the 19th century although at this time the nature of the species was not understood. The behaviour was initially rationalised by polymers, according to the theory proposed by Thomas Graham which considered them as colloidal aggregates of small molecules held together by the forces which are unknown.

The potential of polymers to provide innovative accessible and cheap materials was grasped immediately. 

Hermann Staudinger in 1920 published his seminal work uber polymerisation in which he proposed that polymers were the long chains of atoms which are linked by covalent bonds. 

Long after many debates his work was also accepted, he was awarded the Nobel prize in 1953.

Polymers entered a golden age after the 1930s during which new types were discovered and quickly given commercial applications. 

Nomenclature

For naming polymer substances the multiple convention is used. Many of the polymers which are used commonly such as those found in consumer products are referred to by a common or trivial name. Based on the historical precedent the trivial name is assigned for popular uses rather than a standardized naming convention. Both the IUPAC and the American chemical society(ACS) have proposed standardized naming conventions. The IUPAC and ACS are similar to each other but are not identical.

The Example of Different Namings by Different Institutions are Given below:

In both the conventions the polymer names are intended to reflect the monomers from which they are synthesised from the simple alkane ethane called polyethylene.

[Image to be added Soon]

Properties

Depending on the structure of polymers the property of polymers is determined, and they are divided into classes according to their physical base. Many chemical and physical properties describe how a polymer behaves as a continuous macroscopic material. These are classified as bulk properties according to thermodynamics, intensive properties. Mechanical properties: the polymers bulk properties are those most often of end use internet. These properties are the properties which dictate how the polymer behaves on a microscopic scale. Tensile strength, young’s modulus of elasticity also comes under this.

Transport properties: diffusivity like transport properties are included in this. These are very important in many of the applications crystallization and melting, glass transition, mixing behaviours come under this.

There are many more properties which include chemical properties, electrical properties and optical properties. 

Applications

Synthetic polymers are nowadays used in almost all walks of life. Modern society would look very different from them. The polymer spreading use is connected to their unique properties low cost, low density, good thermal/electrical insulation, high resistance to corrosion, low energy demanding polymer manufacture and facile processing into the final product. 

The properties for a given application of polymer can be turned or enhanced by combination with other materials as in the composites. Polymers application allows to save energy, protect food and drinking water, save land and reduce the use of fertilizers, preserve other materials and protect lives. 

Accessories, clothing, sports wear: PVC clothing and polyester, spandex and sports shoes, footballs west, billiards ball, skis and snowboards, rackets etc. 

Electronic and photonic technologies, containers and packaging, car parts, security, money, separation technologies.

JEE Main Chemistry Chapter-wise Solutions 2022-23 

Important Related Links for JEE Main 2022-23