Common Polymers
Polymers consist of large molecules which consist of long chains of building blocks known as monomers linked together in chemical bond. The way these chains interlink between themselves determines the property of the polymeric material.
When these polymer chains are oriented randomly, they make the product shapeless. But, they exhibit good impact strength and toughness. Some examples are polyvinyl chloride (PVC), polycarbonates and polystyrenes.
In case, these chains are formed in an orderly, densely packed arrangement, the product is formed in crystal form. These crystals show less flexibility and elongation compared to amorphous polymers. Some examples of this type are polyamides like nylon, polyethylene, polypropylene, polyesters etc.
These polymers again could be classified either as thermoplastic or thermoset. This actually indicates the strength of bonding of chains in the polymer. In case of thermoplastic materials, these bonds are quite weak. Therefore, when these polymers are heated, the adjacent chains could slide past one another if sufficient heat is applied. Therefore, these materials could change shape when heated and these products could be recycled for farther use.
But in case of thermoset polymers, the bond between adjacent chains is quite large and it does not allow changing the shape of the product made out of this type of material. Instead, when they are heated they start decomposing chemically.
A list of some of the common polymers is given below along with the applications where they are used:
Phenol Formaldehyde Plastic
This is the first polymer developed for commercial use. It is thermosetting in nature. It was used for producing products like radio and telephone. It is brittle in pure form but could be strengthened using fillers like cellulose and wood pulp. One well known product of this group is Bakelite.
Polystyrene
It is a thermoplastic polymer. It is quite extensively used as economical packaging material. It is also used to make pens, safety razors, CD jewel boxes etc. In its Styrofoam form, it can be easily molded into different shapes for packing of different items.
Polyamide
It is popularly known as Nylon. It is thermoplastic in nature. It is used to make parts where lubrication is a big factor like bearings and gears. It is also used for blow molding and widely used for making textile products.
Polyvinylchloride (PVC)
It is a thermoplastic polymer extensively used to make pipes, wire and cable insulation and in medical applications.
Polyethylene
It is the most common plastic in use. It is thermoplastic in nature. Some of its use in making beverage bottles, car petrol tanks etc.
Polyester
It is a thermoplastic material used to produce textiles and door handles.
Epoxy
It is a thermosetting polymer used as adhesives.
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