Polymers are widely used in appliances, carry bags, furniture, food and agriculture etc. First natural, then synthetic, semi-conductive scientists are coming up with various types of polymers. In this article I will learn about polymers, their physical properties and characteristics.

What Are Polymers?

A large molecule that is essentially a combination of many subunits is known as a polymer. In the Greek term polymer means ‘many parts’. Polymers can be found around us easily, from polypropylene, known as plastic, to biopolymer, which can be found in strands of our DNA.

Polymers that can be naturally obtained from animals and plants are known as natural polymers and are man – and made known as synthetic polymers. Different types of polymers have different qualities, chemical properties, and different uses.

Physical Properties of Polymer

1. Tensile strength – The strength of the polymer to extend without breaking is its tensile strength property. PAI – Polyamide-imide (PAI) has the highest tensile strength among any plastic at 21,000 psi. The durability and physical strength of the polymer depend on this property of the polymer.
2. Melting Point and Boiling Point – melting point and boiling point of polymers are high. The stronger the intermolar forces, the longer the chains, which results in high boiling and melting point.
3. Hardness – Hard polymers are resistant to the penetration of a hard substance into them. As a result of remaining unaffected after wear and tear, it got recognised as ideal for constructing devices.
4. Density – Polymers can be classified as high-density and low-density polymers based on the density level of the different polymers.
5. Heat Capacity / Heat Conductivity – The stiffness of the molecules decides whether or not a polymer is a good conductor of heat. It also helps in deciding to what extent the polymer can act as a good insulator of heat.
6. Thermal Expansion – This property helps in determining how much the polymer can expand and contract in response to heat and cold.
7. Crystallinity –This property of a polymer is based on the arrangement of polymeric chains. The amount of crystalline in a polymer determines the regulation of its chains. The more crystalline, the more often aligned the chains of the polymer. An increase in the measure of crystalline increases density and hardness.
8. Elasticity – The elasticity of polymers is correlated to the intermolecular bonds. Weak intermolecular bonds result in greater elasticity.
9. Permeability – Permeability is the tendency of passing particles through the polymers. For instance, polyethene is a deal to pack food items as it’s less permeable to air.
10. Refractive Index– Refractive index is the measurement of the extent to of light bends as it passes the polymer. This property of a polymer is used in spectroscopy.
11. 11. Resistance to Electric current – Polymers are not generally good conductors of electricity, but they can be used as semiconductor devices such as conductive polymers. Due to conjugated carbon+carbon, double bonds conductivity of polymers arises.

Characteristics of Polymers

1. Chemicals are not a problem for polymers. Look around your home and see all the plastic containers for cleaning fluids. If you read the warning labels for these chemicals, you will see how chemical resistance is highlighted when the chemical is in contact with skin or eyes or ingested. 
2. Polymers are insulators both thermally and electrically. As you walk around your home, you will notice that there are many things made or covered with polymeric materials, such as appliances, cords, electrical outlets, and wiring. The thermal properties of polymers are evident in the kitchen, such as pot and pan handles, refrigerator and freezer foam cores, insulated cups, coolers, and microwave cookware. The thermal wear that skiers wear is also constructed of polypropylene.
3. Polymers are lightweight but come in a variety of strengths. From toys to space station structures, or delicate nylon fibre in pantyhose to bulletproof vests made from Kevlar, these materials have a wide range of applications.
4. A polymer can be processed in a variety of ways to create thin fibres or intricate products. In addition to being moulded into bottles and cars, plastics can also be mixed with solvents to form adhesives and paints. Plastics and elastomers are very flexible. Polystyrene (StyrofoamTM) and urethane are also examples of polymers that can be foamed.

Conclusion

In the above article, we learned that polymers could be found easily from DNA strands to plastic around us. There are many uses for polymers. Every type of polymer has different durability and uses. We talked about the physical properties of the polymer and its characteristics.