Question

Shyam went to a grocery shop to purchase some food items. The shopkeeper packed all the items in polythene bags and gave them to Shyam. But Shyam refused to accept the polythene bags and asked the shopkeeper to pack the items in paper bags. He informed the shopkeeper about the heavy penalty imposed by the government for using polythene bags. The shopkeeper promised that he would use paper bags in future in place of polythene bags.

1) Write the values (at least two) shown by Shyam.

2) Write one structural difference between low-density polyethene and high-density polyethene.

3) Why did Shyam refuse to accept the items in polythene bags?

4) What is a biodegradable polymer? Give an example.

 

Answer 1

1) The following are the values shown by Shyam-

• protection of the environment
• knowledge about biodegradable and non-biodegradable polymers.

2) 

The low-density polymer was the first Poly-ethylene to be developed. It has low-density levels and only a small amount of branching. It is very flexible and easy to clean. It is often used to make plastic film wrap and plastic bags. Additionally, it is used to make plastic items that need to be moulded, such as plastic bottles used in labs and some prostheses.

The high-density polymer has higher density levels; it is also characterized by a linear structure consisting of no branching. That makes high-density polymer stronger and more resistant to chemicals. It is most commonly used for items requiring blow moulding techniques, such as toys, automobile parts and bottles. For example P.V.C.

3) Shyam refuses to accept the items in polythene bags because polymers are non-biodegradable polymers i.e. they cannot be decomposed by natural processes. So, they have harmful effects on the environment.

4)A polymer that can be decomposed by bacteria is called a biodegradable polymer.

Poly- β -hydroxybutyrate-CO- β - hydroxyvalerate (PHBV) is a biodegradable polymer.