Question

1. Name the man-made fibre which is regarded as artificial silk.
2. What is polymer? Name the natural polymer of which cotton is made
3. Differentiate between thermoplastic and thermosetting plastics.
4. Explain why the disposal of plastic wastes is a major problem. Give two reason.
5. What do you mean by synthetic fibres? Write two characteristics and uses of rayon and Nylon ​

Answer 1

Explanation:

Ans 1 ) Rayon- Rayon is synthesized from wood pulp. Rayon resembles silk, so it is also known as artificial silk.

Ans 2 ) Polymers are materials made of long, repeating chains of molecules. The materials have unique properties, depending on the type of molecules being bonded and how they are bonded. Some polymers bend and stretch, like rubber and polyester. ... The term polymer is often used to describe plastics, which are synthetic polymers Cellulose helps the plants to remain stiff and strong and as a source of fibre its importance exists in dietary form. Cotton consists of a long chain of glucose molecules and thus occurs naturally in plants and thus it is composed of pure cellulose which is the naturally occurring polymer.

Ans 3 ) The primary difference between the two is that Thermoset is a material that strengthens when heated, but cannot be remolded or heated after the initial forming, while thermoplastics can be reheated, remolded, and cooled as necessary without causing any chemical changes.

Ans 4 ) Disposal of plastic waste is a major problem because:

1)The articles made of plastic are non-biodegradable. They do not decompose easily. 2)The burning of plastic gives out harmful gases which pollute the air.

Ans 5 ) Rayon- Rayon is synthesized from wood pulp. Rayon resembles silk, so it is also known as artificial silk. Rayon can be dyed in different colours and is much cheaper than silk. ... Nylon is synthesized from coal, water and air. Nylon is very strong and its fabric is like silk.