IMPORTANT TERMS

Polymer                       - A large molecule formed by the combination of many small molecules.

Biodegradable              - Material that gets decomposed through natural processes.

Non-biodegradable       - Material which is not easily decomposed through natural processes.

Teflon                          - A special plastic on which water and oil do not stick, suitable for cookwares.

 

SYNTHETIC FIBRES

Fibres that are made by human beings using chemical substances are called synthetic fibres. They are also known as man-made fibres. Synthetic fibres are obtained from chemical processing of petrochemicals. Rayon, Nylon, Polyester, Acrylic are examples of synthetic fibres.

 

PROPERTIES AND USES OF RAYON

Rayon is also known as ‘Artificial Silk’. It is prepared from cellulose, which comes from wood pulp. Pure cellulose is extracted and processed under control conditions to form fibres.

• It is shiny and lustrous and resembles silk in appearance.
• It absorbs sweat and is therefore preferred over other synthetic fibres in summers.
• Rayon is used for making shirts, curtains, tablecloths, etc.

 

PROPERTIES AND USES OF NYLON

Nylon is the first true synthetic fibre. It was first produced by the scientists at the DuPont Company from coal, water and air in 1930s.

• It is strong, elastic, lustrous and easy to wash.
• Due to its high strength, it is used for making parachutes and ropes for rock climbing, tennis racquets.
• It is used for making saris, stockings, umbrellas, toothbrush bristles etc.

 

PROPERTIES AND USES OF POLYESTER

Polyester is made up of the repeating units of a chemical called ‘Ester’.

• It is very lightweight, strong and has good elasticity.
• Fabric made from polyester does not wrinkle easily and comes back into shape when creased.

• Polyester is used for making dress materials.
• It is also used for making lightweight sails, fire hoses etc.
• The most commonly used polyester is Terylene.

PROPERTIES AND USES OF ACRYLIC

Acrylic also known as Orlon, is a fibre that closely resembles wool.

 

• It is warm, soft, light and flexible.
• It is resistant to moths and chemicals.
• It is used for making sweaters, shawls, blankets and carpets.

 

Summary

Name of Fibre	Properties of Fibre	Uses
Rayon	Shiny, lustrous, sweat absorbing, resembles silk	Shirts, home furnishing like Bed sheets, curtains, tablecloths
Nylon	Elastic, lustrous, strong, easy to wash	Saris, stockings, umbrellas, toothbrush bristles, climbing ropes, parachutes
Polyester	Strong, lightweight, good elasticity,	lightweight sails, fire hoses,  dress materials
Acrylic (Orlon, Acrilan)	Warm, soft, light, flexible, resembles wool	Sweaters, shawls, blankets
Spandex (Lycra)	Excellent elasticity	Swimming costumes, T-shirts

 

BLENDED FIBRES

Blended fibres are the fibres that are created by combining two different fibres. Some of the common blended fibres are polycot, terrywool, cotswool etc.

 A mixture of wool and cotton is known as Cotswool.

Polywool or Terrywool is a combination of polyester or terylene, a type of polyester and wool.

Polycot or terrycot is a combination of cotton and polyester or terylene.

CHARACTERISTICS OF SYNTHETIC FIBRES

Synthetic fibres have many advantages over natural fibres.

• Synthetic fibres are durable, strong and have good elasticity.
• They do not wrinkle easily and are easy to maintain.
• They are less expensive as compared to natural fibres.

 

DISADVANTAGES OF SYNTHETIC FIBRES

Synthetic clothes catch fire easily, so it is not safe to wear them while cooking.

Most of the fabrics made from synthetic fibres do not absorb moisture, which makes them uncomfortable to wear during the summer season.

 

PLASTICS

Plastics are polymers like synthetic fibres. In some plastics, the arrangement of the monomer units is linear, while in others the arrangement is cross-linked.

THERMOPLASTICS

 

Plastic that gets deformed easily on heating and can be bent easily is known as ‘Thermoplastic’. Polyvinyl Chloride (PVC) and Polypropylene (PP) are the examples of thermoplastics. These are used for manufacturing toys and various types of containers.

DIFFERENT TYPES OF PLASTICS AND THEIR USES

Variety of Plastics	Uses
Polyethylene terephthalate (PET)	Making bottles of carbonated beverages
Polyvinyl Chloride (PVC)	Making pipes for sanitary fitting such as water pipes
Low-density polyethylene (LDPE)	Making grocery bags and poly bags
High density polyethylene (HDPE)	Making containers for strong and corrosive household and industrial chemicals such as acids.
Polystyrene (PS)	Thermocol, a form of PS, is used for making disposable cups
Polypropylene (PP)	Making medicine bottles, yogurt containers

 

THERMOSETTING PLASTICS

Thermosetting plastics do not get deformed or re-moulded on heating when once moulded.

Melamine and Bakelite are the examples of thermosetting plastic.

 

PROPERTIESOF PLASTICS

Plastics are non-reactive to water, air and chemicals and do not get corroded easily.

Plastics are durable and long lasting and are therefore, used to make parts for aircrafts and space-crafts.

Plastic is insoluble in water and is used for making buckets, bottles and containers for storing water and various chemicals.

Plastics are poor conductors of heat so they are used for making handles of cooking vessels.

Plastics are poor conductors of electricity so they are used as covering materials in electrical wirings.

 

PLASTICS AND THE ENVIRONMENT

 

Despite the various uses of plastic, its disposal is a serious problem. Most of the methods used to dispose them result in some type of damage to the environment.   

 

Plastic is a non-biodegradable material and it takes several years to decompose.

 

In the process of burning, plastic produces toxic gases into the atmosphere, which is a source of air pollution.

 

When plastics are thrown carelessly, they often choke the drains and harbour many organisms that spread diseases.

 

Plastic bottles cause the death of many marine animals when they are mistaken for food.

 

INTERESTING FACTS

 

• Cashmere, also known as the fibre of kings, is produced from the fine, soft undercoat of hair of the Kashmir goat.
• Plastic needs about 450 years just to start decomposing. Then, it takes another 50-80 years to decompose completely.
• Recycling a single plastic bottle can conserve enough energy to light a 60W bulb for up to 6 hours.
• Nylon was historically developed as a synthetic substitute for silk.
• Plastic bags, bottles, and other garbage that end up in the ocean kill around 1 million sea creatures every year.