Synthetic Fibres and Plastics: Properties and Types

I. Types of Fibres

There are two types of fibres:

• Natural fibres: Obtained from natural sources (e.g., cotton, silk, wool).
• Synthetic fibres: Man-made fibres (e.g., rayon, nylon, acrylic).

II. Understanding Polymers

A synthetic fibre is a chain of small units of chemical substances joined together. Many such single units combine to form a single unit called a polymer. The term polymer means "made of many units joined together."

III. Types of Synthetic Fibres

• Rayon: Synthesized from wood pulp. It resembles silk, so it is also known as artificial silk. Rayon can be dyed in different colours and is much cheaper than silk.
• Nylon: The first commercially synthesized fibre. It is made from coal, water, and air. Nylon is very strong and its fabric resembles silk.
• Polyester: One of the most popular man-made fibres. It is made of repeating units of a chemical called ester and is widely used to make clothes.
• Acrylic: A man-made fibre known as artificial or synthetic wool because it resembles wool. Acrylic is cheaper than natural wool, can be dyed in various colours, and is very popular.

IV. Characteristics of Synthetic Fibres

• Synthetic fibres are cheaper than natural fibres.
• They are stronger than natural fibres.
• They are more durable than natural fibres.
• Synthetic fabrics dry in less time.
• They are easy to maintain and wash.

V. Plastics

Plastic is a polymer that can be recycled, coloured, reused, moulded, or drawn into wires or various other shapes. Units of some plastics have a linear arrangement, while others are formed by a cross-linked arrangement. Plastic is used in making toys, suitcases, bags, cabinets, brushes, chairs, tables, and many other items. Polythene is one of the most famous types of plastic, used in the manufacturing of carry bags.

Types of Plastics

1. Thermoplastic: Plastics that can be easily bent or deformed upon heating. Examples include PVC and polythene.
2. Thermosetting plastic: Plastics that do not get deformed or softened on heating once moulded. Examples include Bakelite and melamine.

Characteristics of Plastics

• Plastic is a poor conductor of heat and electricity.
• Plastic does not react with air, water, or many chemicals.
• Plastics are lightweight, durable, cheap, and very strong.
• Plastics are non-biodegradable. They take many years to decompose or may not decompose at all, making them unfriendly to the environment.
• Plastic does not rust.