SYNTHETIC FIBRES

AND PLASTICS

SYNTHETIC FIBRES The fibres made by human beings are called

synthetic fibres or man-made fibres. Synthetic fabrics are textiles made from man-

made rather than natural fibres. Examples : Polyester , ozone , acrylic , nylon , rayon etc.

A synthetic fibre is also a chain of small units joined together . Each small unit is actually a chemical substance. Many such small units combine to form a large unit is called polymer.

Polymer occur in nature also . Cotton , for example , is a polymer called cellulose. It is made up of a large number of glucose units.

TYPES OF SYNTHETIC FIBRES RAYON

A textile fibre or fabric made from regenerated cellulose ( viscose ) and the artificial silk is called rayon. It is having as beautiful structure like of silk. It was obtained from chemical treatment of wood pulp. It is a man-made fibre. It is cheaper than natural silk and can be woven like silk fibres. It can be also dyed into wide variety of colours. It is mixed with cotton to make bed sheets or mixed with wool to make carpet.

NYLON Nylon is a man-made fibre. It is a tough,

lightweight, elastic synthetic polymer with a protein like chemical structure. It is made without using any natural material. It was prepared from coal, water and, air. It was the first fully synthetic fibre. It was lustrous and easy to wash. The things made from it are socks, ropes, tents, tooth brushes, car seat belts, sleeping bags etc. It is also used for making parachutes and ropes for rock climbing. A Nylon thread is actually stronger than a steel wire.

POLYESTER Polyester is a man made fibre. Fabric made

from this fibre does not get wrinkled easily. It remains crisp and is easy to wash. Terylene is a popular polyester.

PET ( Polyethylene Terephthalate ) is a familiar form of polyester. It is used for making bottles, utensils, films and many other useful products.

Polyester ( Poly+Ester ) is actually made up of repeating units of a chemical called ester.

ACRYLIC Sweaters and shawls or blankets which we use

in winters are not made purely form natural wool, they are made up of another type of synthetic fibre called acrylic.

The wool obtained from natural resources is quite expensive, whereas cloths made from acrylic are relatively cheap.

Synthetic fibres are more durable and affordable which makes them more popular than natural fibres.

PETROCHEMICALS All the synthetic fibres are prepared by a

number of processes using raw materials of petroleum origin, called petrochemicals.

Petrochemicals, also called petroleum distillates, are chemicals product from petroleum

Some chemicals compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as corn or sugar cane.

CHARACTERISTICS OF SYNTHETIC FIBRES

They dry up quickly. They are cheap. They are readily available. they are easy to maintain.

PLASTICS Plastic is also a polymer like the synthetic

fibre. All plastic do not have the same type of arrangement of units. In some it is liner whereas in other it is cross-linked. Plastic articles are available in all possible shapes and sizes.

The fast is that plastic is easily mouldable i.e. can be shaped in any form. Plastic can be recyled, reused, coloured, melted, rolled into sheets or made into wires. That is why it is finds such a variety of uses.

THERMOPLASTICS Plastic which gets deformed easily on

heating and bent easily are known as thermoplastics.

Examples of thermoplastics are: Polythene, PVC etc.

Thermoplastics are used for manufacturing toys, combs and various types of containers.

THERMOSETTING PLASTICS There are some plastics which when

moulded once, cannot be softened by heating. These are called thermosetting plastics.

Examples of thermosetting plastics are: Bakelite and Melamine.

BAKELITE Bakelite is a poor conductor of heat and

electricity. It is used for making electricial switches, handles of various utensils etc.

Polyoxybenzylmethylenglycolanhydride is an early plastic. It is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde.

MELAMINE Melamine is a versatile material. It resist

fire and can tolerate heat better than other plastics.

It is used in uniforms of firemen having its coating which is flame resistant.

It is used for making floor tiles, kitchenware and fabrics which resist fire.

PLASTIC Plastic is used for storing a food item,

water, pickles, milk, etc. this is because of their light weight, lower price, good strength and easy handling.

Plastic are non-reactive. They do not react with water and air. They are not corroded easily.

PLASTICS - LIGHT, STRONG AND DURABLE

Plastic is very light, durable, strong and, can be moulded into different shapes and sizes.

Plastics are generally cheaper than metals. They are widely used in industries for making home articles.

Plastic containers are used to store food materials.

PLASTICS-POOR CONDUCTORS Plastics are poor conductors of heat and

electricity because it has no delocalised electrons. And the number of delocalised electrons in a substance determines its ability to transfer heat. So, electrical wires have plastic covering, and handles of screw drivers are made of plastic. Handles of frying pans are also made of plastic.

USES OF PLASTICS Plastic is used extensively in health care

industry. Some examples of its use are packaging of tablets, threads used for stitching wounds, syringes, doctor’s gloves and a number of medical instruments.

Plastic cookware is used in microwave ovens for cooking food. In it, the heat cooks the food but does not affect the plastic vessel.

Teflon is a special plastic on which oil and water do not stick. It is used for non-stick coating on cook wares.

PLASTICS AND THE ENVIRONMENT A material which gets decomposed through

natural processes by bacteria called biodegradable.

Plastic takes several years to decompose, it is not environment friendly. It causes environmental pollution. When it is burned, it releases lots of poisonous fumes into the atmosphere causing air pollution.

A material which is not easily decomposed by natural processes is called non-biodegradable.

COWS EATING GARBAGE FOOD Cows some time eat the garbage food present

in the garbage dump. In the process of eating the food waste, they swallow the polythene bags and wrappers of food.

We should not throw polybags here and there especially in drains clogging it.

As a responsible citizen we should not throw garbage and wrappers of food like chips, biscuits etc. on the roads or in parks and picnic places.

FIBRE - WISE Do not throw plastic bags in the water

bodies or on the road. Take a cotton carry bag or a jute bag

while going for shopping instead of plastic bags.

Try to minimise the use of plastic materials. For example : use a steel lunch box instead of plastic lunch box

THANK YOUPREPARED BY- Ayush Singh