Synthetic fibres and plastics Worksheet-3

Synthetic fibres and plastics Worksheet-3

 

  1. What is polyester?

 

  1. Name the fabric obtained by mixing polyester and cotton.

 

  1. How are synthetic fibres made?

 

  1. Name the plastic which is used for insulating electric wires.

 

  1. Name the plastic which is used for making pipes for insulating electric installations.

 

  1. What is the difference between thermosetting plastics and thermoplastics?

 

  1. Why are the chemicals in the laboratory stored in plastic containers?

 

  1. Can you store pickles in plastic containers? Why?

 

  1. Why are the electric wires covered with plastic?

 

  1. Which property of plastic makes it suitable to be used for making handles of frying pans?

 

  1. Why do we use plastic cookware in microwave ovens?

 

  1. What are biodegradable materials?

 

  1. What are non-biodegradable materials?

 

  1. Tin takes about 100 years to degenerate. Is it biodegradable or non-biodegradable?

 

  1. As a responsible citizen, what are the 4R's we should remember?

 

Answer:

  1. Polyester is a polymer consisting of repeating units of ester. Ester is a chemical compound.

 

  1. Polycot is obtained by mixing polyester and cotton.

 

  1. Petrochemicals are used for making synthetic fibres. The chemicals are polymerized under different conditions of temperature and pressure to make synthetic fibres.

 

  1. Polyethylene (polyethene ) is used for insulating electric wires.

 

  1. P.V.C (polyvinyl chloride ) is used for manufacturing pipes for insulating electric installations.

 

  1. Thermoplastic on heating gets softened and can be remoulded. For example: Polyethene, PVC

Thermosetting plastics do not soften on heating and once molded cannot be remolded.

For example: Bakelite, Melamine

 

  1. Plastics are inert materials. They do not react with air, water or chemicals.

Hence chemicals are stored in plastic bottles.

 

  1. Yes pickles can be stored in plastic containers because they are not corroded as they do not react with air and water.

 

  1. Plastics are poor conductors of electricity hence electric wires are covered with plastics.

 

  1. Plastics are poor conductors of heat hence it is used for making handles of frying pans.

 

  1. Polypropylene a kind of plastic which is used for making cookware for use in microwaves because of its high heat resistance. The food gets heated up but the cookware does not.

 

  1. The materials which can be decomposed by microorganisms are called biodegradable materials.

For example: Polymers like cellulose, starch, proteins are common examples of biopolymers which are biodegradable also.

 

  1. The materials which cannot be decomposed by microorganisms are called non-biodegradeble polymers. For example: Polyethene, PVC, Polystyrene etc

 

  1. Tin is not biodegradable material as it is a metal and is not decomposed by microorganisms.

 

  1. The 4R’s we should remember are Reduce, Reuse, Recycle, Recover.