Synthetic Fibres And Plastics

Fibres that usually made using natural materials along with some manmade materials are known as synthetic fibre.

Wood pulp is made into a complex compound and thus it is utilised to make Rayon.

Polycot is a fabric which is a mixture of cotton and polyester fibres. Cotton is a Natural Fibre and Polyester fibres are man made.

Melamine is a Thermosetting plastic as it cannot be re-shaped once it is being moulded in a particular shape.

Rayon is a type of fibre that can be changed into other fibres easily. Moreover, its properties are similar to that of natural fibres.

Bakelite acts as an insulator. That is, it doesn’t allow heat to pass through it. Thus, it is used in kitchens, where there are risks of overheating.

Plastic is an insulator. It does not electricity to pass through it. For a substance to conduct, there must be the availability of free electrons which is not in the case of plastics.

Nylon is an artificial fibre - manmade, PVC is a Thermoplastic- materials whose shape and size can be easily changed, and Bakelite is a Thermosetting plastic – Its shape and size cannot be changed once fixed.

All the three are artificial – That is, made by humans.

PET stands for polyethylene terephthalate. It is strong, light weight and also feasible. Therefore, it is used for making kitchen containers.

Cotton is 99% cellulose.
Hence, the chemical name of cotton is Gossypium. Natural fibres are fibres that are produced by plants, animals and geological processes.

Its common name is Rayon. It is commonly known as artificial silk as it has similar properties to that of silk.

Terrycot is made by mixing Terylene and Cotton. Cotton is a Natural Fibre and Terylene is an Artificial Fibre.

Plastics can be easily moulded and thus can take any shape and size easily and hence are used to make a variety of objects. Moreover, they are insulators. Making them in the required shape is very easy when compared to other materials.

Plastics are a very big cause to pollution. They are Non-Biodegradable. That is, take thousands of years to decompose and are a threat to human life.

Burning plastics releases a lot of harmful gases that play a role in increasing pollution. The harmful gases released causes a lot of breathing problems to humans.

The biodegradable materials are (a), (b), (c), (f). All these decompose easily unlike the rest of the options given above. That is, the complex compounds break down to simpler ones and go in the soil.

Iron is a very reactive metal. Thus, it reacts with air and moisture present in the atmosphere and gets corroded easily – A brown coloured layer is developed on the surface. This does not happen in the case of plastics as it is non-reactive.

Nylon ropes are the strongest, have high elastic properties and are also lighter when compared to jute ropes. Thus, they are used to make ropes, especially when it comes to mountain climbing. Jute ropes are comparatively weaker and using it to make ropes for mountaineering can be risky for the climbers.

Acrylic blankets are cheap, comfortable, light and also available in a wide range of colours. It is also washable unlike blankets made of wool. Acrylic is a Synthetic fibre whereas wool is a natural fibre.

Thermoplastics on heating get deformed (its shape and size can be altered) and thus can also be bent. On the other hand, thermosetting plastics cannot be bent once moulded. Some examples of Thermoplastics are – Polythene and PVC. Some examples of Thermosetting plastics are – Bakelite and Melamine.

(i) Monomers (Smallest molecules that combine with each other to for complex polymers)

(ii) Man Made (These fibres are not obtained naturally and have to made by doing various chemical reactions)

(iii) Nylon (It was made in 1865 by Wallace Carothers)

(iv) Acrylic (It has properties similar to that of wool)

(v) Melamine (It is a thermosetting plastic)

Nylon- Parachutes (It is light weight and perfectly suited to be used to make parachutes)

PET – Polyester (PET Is a Synthetic Fibre)

Rayon – Artificial wool (Rayon is also known as artificial wool as its properties match with those of wool)

Thermosetting plastics – Electric switches (Thermosetting plastics are extremely strong and are also good insulators)

Teflon – Non-stick coating (Teflon is coated on pans)

(a) Rayon – A synthetic Fibre

(b) Polymer – Combination of a lot of monomers

(c) Terylene – An Artificial Textile

(d) Plastic - Insulator

(e) Polyester – Synthetic polymer

(f) Teflon – Synthetic polymer

(i) True. Tery wool stands for Terylene- Wool

(ii) False. Synthetic fibres melt on heating.

(iii) True, Synthetic cause can melt on heating and thus cause burns.

(iv) False, Plastics are non-biodegradable.

Here is the importance of Synthetic polymers:

1) Due to its excellent elasticity and high strength, it is used to make ropes for rock climbing, fishing nets, parachutes, etc.

2) Acrylic, which is an example of Synthetic fibers, is used to make sweaters, boots, gloves and also in furnishing fabrics and carpets because of its similarity with many natural fibers.

3) Terylene is used to make clothes. It is also mixed with some other fabrics to provide a variety of clothing materials.

4) Plastic containers are one of the most used substances. They are used to store food, liquids and they are also very convenient to use.

5) Synthetic fibres are cheap and thus are feasible to everyone.

Plastics must not be used much because of the following reasons:

1. Plastics are non- biodegradable substances. Decomposing plastics take thousands of years. Thus, the disposal of waste plastics is very difficult.

2. On burning plastics, a lot of harmful gases are released that are harmful to the environment as well as to the humans. Thus, plastics must not be disposed of by burning them.

Take two threads. One made of cotton (A Natural fibre) and the other made of nylon (A synthetic fibre). Attach one end of both the ropes to a rigid support. Now, on the other end, hang a particular amount of weight. Keep adding weights until the cotton thread breaks. You will notice that Nylon has a greater tensile strength than Cotton.

More weight is required to break the nylon rope than the cotton rope.

ACROSS:

1. Acrylic – It is used to make a layer of coating on pans.

2. Polyethene – It is used as plastic bags, containers, etc.

3. Polymer – Formed by combining multiple monomers.

4. Rayon – A type of synthetic fibre having similar properties to that of natural fibres.

DOWN:

5. Silk – A natural fibre usually used to make clothes.

6. Terelene – A manmade fibre used to make linens.

7. Nylon – A synthetic fibre used for making ropes, parachutes.