Plastic too is a polymer. But arrangement of units is different in different types of plastic. In some plastics, the individual units are linked in a linear fashion. In some other plastics, the individual units are cross-linked.
Types of Plastic
Thermoplastic: Some plastics easily get deformed on heating, and can be easily bent and reshaped by heating. They are called thermoplastic. Polythene and PVC are examples of thermoplastic. Thermoplastic is used for making combs, toys, buckets, mugs, etc.
Thermosetting Plastic: Some plastics do not get deformed on heating, and cannot be re-molded into a new shape. Such plastics are called thermosetting plastic. Bakelite and melamine are examples of thermosetting plastic. Bakelite is used for making electrical switches and switchboards because it is a poor conductor of heat and electricity. Melamine is resistant to fire and is hence used for making utensils.
Reasons for popularity of plastic:
Plastic is non-reactive: Unlike iron; plastic does not react with air to form rust. Due to this, plastic has replaced iron from many articles. Plastic does not react with many chemicals, and so, plastic containers are used for keeping many materials and chemicals.
Plastic is light, strong and durable: Plastic is lightweight, strong and durable. Plastic chairs have replaced wooden chairs in most of the households. Wooden crates have been replaced by plastic crates; for keeping milk and cold drinks. Most of the warehouses now use plastic pellets for keeping goods.
Plastic is poor conductor of heat and electricity: Because of poor conductivity to heat and electricity; plastic is used for making switches and many components of electrical appliances. Handles of utensils are made of plastic because such handles do not heat up.
Plastic and the Environment
Biodegradable: A material which can be decomposed by microbes is called a biodegradable material, e.g. jute, cotton, paper, leftover food, etc.
Non-biodegradable: A material which cannot be decomposed by microbes is called a non-biodegradable material, e.g. plastic, iron, copper, etc.
The non-biodegradable nature of plastic poses a big problem. Plastic has become very popular due to many of its inherent benefits. But popularity of plastic is proving to be a curse for the environment. Plastic waste is getting accumulated all around us, in the street, on sidewalk, in drains, on garbage dumping sites, etc. This is creating a burden of plastic waste on the earth.
Harms of plastic bags:
Plastic bag keeps on accumulating in the environment.
It chokes drains.
A stray animal can die if it accidentally swallows plastic bag.
How to tackle the problem of plastic waste?
Follow the principles of three Rs, i.e. Reduce, Reuse and Recycle.
Use recyclable plastic or use shopping bags of cloth or jute.
Do not throw plastic bags on roads or in drains.
Reuse plastic containers for keeping household items.