Problem 17 - A Complete Resource Book in Chemistry for JEE Main

Question

A polymer of ethylene chloride and sodium poly sulphide is? (a) Thiokol (b) Melamine (c) Glyptal (d) Perlon L

Step-by-Step Solution

Answer

The polymer is Thiokol.

Step 1: Understanding the Composition

The problem mentions a polymer of ethylene chloride and sodium poly sulphide. We need to recognize what type of polymer results from these two compounds. Ethylene chloride is known for providing chlorinated elements in polymer chemistry, while sodium poly sulphide is a sulfide compound.

Step 2: Identify Polymer with Sulfide Linkages

A key characteristic to note is the sulfur (sulfide) component from sodium poly sulphide. In the context of polymer chemistry, this indicates rubber-like polymers that incorporate sulfur links. Polymers that meet this description often fall into the category of polysulfide rubbers.

Step 3: Choose the Right Option

Among the given options, 'Thiokol' is known for being a polysulfide rubber. It is specifically made by polymerizing ethylene dichloride (or ethylene chloride) with sodium polysulfide. None of the other options (Melamine, Glyptal, Perlon L) fit this description.

Key Concepts

Understanding Ethylene Chloride

Ethylene chloride is an important compound in polymer chemistry. Its common name is 1,2-dichloroethane. It features two chlorine atoms attached to an ethane backbone. Because of their chlorine content, compounds like ethylene chloride are used to introduce chlorinated characteristics into molecules.

In polymer chemistry, ethylene chloride is often utilized as a building block for more complex compounds. Its chlorinated properties allow for creating materials with unique qualities such as resistance to different chemicals and changes in thermal properties. This makes it highly valuable in producing specialty polymers and materials.

Exploring Sodium Polysulfide

Sodium polysulfide is a chemical compound consisting of sodium (Na) and polysulfides, which are chains of sulfur atoms ( S_n ). These sulfur chains are integral in cross-linking within polymers, giving rise to particular properties.

Sodium polysulfide is used to create polymers known for their elasticity and rubber-like behaviors. When sodium reacts with polysulfide, it gives the compound reactive properties, which are essential for forming bonds in different polymerization reactions. This makes sodium polysulfide a key player in producing synthetic rubbers and various industrial applications.

What is Polysulfide Rubber?

Polysulfide rubber, also called Thiokol, is a synthetic rubber developed by polymerizing ethylene chloride and sodium polysulfide. Known for its excellent resistance to oils, solvents, and chemicals, it is very durable.

This type of rubber features sulfide linkages which contribute to its high elasticity and ability to restore its shape after deformation. Polysulfide rubber is often utilized in automotive, aerospace, and construction industries due to its unique properties. Its elastomeric nature makes it suitable for sealing and waterproofing applications.

• High chemical and oil resistance
• Elastic and flexible
• Used widely in specialized industrial applications