Problem 97 - Advanced Problems in Organic Chemistry for Competitive Examinations

Question

The monomers used in the manufacture of nylon-6, 6 are (a) adipic acid and butadiene (b) sebacic acid and hexamethylene diamine (c) sebacic and butadiene (d) adipic acid and hexamethylene diamine

Step-by-Step Solution

Answer

Option (d) adipic acid and hexamethylene diamine are the monomers for Nylon-6,6.

Step 1: Understand Nylon-6,6

Nylon-6,6 is a type of synthetic polymer obtained through the condensation polymerization process. It is typically made from two specific types of monomers.

Step 2: Identify Monomers for Nylon-6,6 Synthesis

The monomers used in the production of Nylon-6,6 are hexamethylene diamine and adipic acid. These two compounds react together to form the polymer chain of Nylon-6,6.

Step 3: Analyze Given Options

Compare the given options to the identified monomers. Option (d) lists adipic acid and hexamethylene diamine, which matches the monomers required for Nylon-6,6 synthesis.

Step 4: Confirm Correct Answer

Based on the synthesis process of Nylon-6,6, option (d) is correct as it includes both adipic acid and hexamethylene diamine, which are necessary for creating the polymer.

Key Concepts

Condensation Polymerization

Condensation polymerization is a key process used in creating many synthetic polymers, such as nylon-6,6. In this process, monomers with two functional groups, like amines or carboxylic acids, react together. One of the most identifying features of condensation polymerization is that it results in the loss of small molecules. Typically, water or methanol is released as by-products. This is fundamentally different from addition polymerization, where no such by-product is formed.

Think of condensation polymerization as a way to "combine" bricks to create a strong polymer chain. Each monomer represents a brick with sticky ends due to its functional groups. As these bricks attach, they release small molecules, making the chain longer. Over time, this process yields strong, durable polymers such as nylon-6,6. In the case of nylon-6,6, the two main ingredients, adipic acid, and hexamethylene diamine, react to create the nylon polymer, showcasing how essential condensation polymerization is.

Adipic Acid

Adipic acid is one of the key ingredients used in the synthesis of nylon-6,6. It is a type of dicarboxylic acid with the formula \((\text{C}_6\text{H}_{10}\text{O}_4)\). Known for its six-carbon structure, it has two carboxylic acid groups that enable it to react effectively with amines.

• Adipic acid is commonly used not only in nylon production but also in the food and medical industries.
• In the context of nylon-6,6 synthesis, the role of adipic acid is crucial as it provides the acid groups required for condensation with hexamethylene diamine.

By knowing about adipic acid, we understand a critical part of the nylon-6,6 production process. It binds with hexamethylene diamine to form long chains of nylon, emphasizing the importance of this compound in creating synthetic fibers.

Hexamethylene Diamine

Hexamethylene diamine is another essential monomer in the formation of nylon-6,6. Its chemical formula is \((\text{C}_6\text{H}_{16}\text{N}_2)\), and it features two amine groups. These groups are highly reactive and form the backbone for many types of synthetic materials.

Hexamethylene diamine is particularly known for its role in pairing with adipic acid to create nylon-6,6. Here’s how it works:

• The amine groups react with the carboxylic acid groups of adipic acid.
• This reaction leads to the formation of amide bonds, which are strong links responsible for the polymer’s strength and durability.
• The release of water molecules in the reaction is a characteristic feature of condensation polymerization, as mentioned earlier.

Therefore, hexamethylene diamine is not just another chemical but a foundation for creating robust synthetic fibers like nylon-6,6. Understanding its functionality is key to grasping how condensation polymerization successively builds up these important materials.