The Age of Plastics

Ø Give some examples of fibres. (cotton, wool, silk, jute, nylon etc)

(answer may vary, accept all correct answers)

Ø Is cotton natural or synthetic fibre? (natural fibre)

Ø What is synthetic fibre?

fibres such as cotton, wool, silk, jute etc. are

obtained from plants or animals. Such fibres are known as natural fibres.

· Inform that, fibres which are synthesised by human beings are known as

synthetic or man-made fibres. There are several synthetic fibres such as rayon,

nylon, acrylic, polyester etc.

Ø How is the necklace formed? (by joining the beads together)

Ø What is the synthetic fibre made up of?

Ø How is the synthetic fibre formed?

many beads are joined together in a

string to form a long necklace. Similarly, a synthetic fibre is a long chain of

several small parts joined together.

· Inform that, a substance formed by joining of many small parts is known as

polymer (poly = many; -mer = part). Each part in a polymer is known as a

monomer (mono = one; -mer = part).

each bead can be considered as a monomer and the necklace as

polymer many small units come together and are joined chemically to form a

polymer. This process of formation of a polymer is known as polymerization

Ø From which source cotton fibre is obtained? (cotton plant)

Ø From which source synthetic fibres are obtained?

· Explain that, synthetic polymers are manufactured in industries mainly from the

by-products of crude oil and petroleum, also known as petrochemicals.

· Inform that, the raw materials can also be obtained from fossil fuels, such as,

coal and natural gas.

Ø What is the most commonly used synthetic fibre? (nylon)

Ø How it is formed?

· Inform that, Nylon is arguably the most commonly used synthetic fibre in the

world. Inform that, nylon is completely synthesised in industries without using any

natural raw materials. It is thus considered the first fully synthetic fibre.

What is the difference between natural and synthetic fibres? (natural are

obtained from plants or animals and the synthetic fibres are synthesised by

human beings)

Ø Do you think natural fibre is better than synthetic fibre or vice-versa

Ø Name two polyester fibres. (terylene and polyethylene terepthalate)

Ø You must have heard about /or wore Terrycot /Terrywool clothes. From which

fibres terrycot is made up of? (terylene and cotton)