Problem 166 - Advanced Problems in Organic Chemistry for Competitive Examinations

Question

Which of the following fibres is made of polyamides? (a) Raon (b) Orlon (c) Nylon (d) Dacron

Step-by-Step Solution

Answer

Nylon is the fibre made of polyamides.

Step 1: Identify Polyamide Fibres

Polyamides are a class of synthetic fibers. The key characteristic of polyamides is that they contain repeating units linked by amide bonds. To solve the problem, we need to identify which of the options is a polyamide.

Step 2: Analyze Each Option

- Rayon: This is a semi-synthetic fiber made from cellulose, not a polyamide. - Orlon: This is a brand name for fibers made from polyacrylonitrile, also not a polyamide. - Nylon: This is a synthetic polymer, specifically a polyamide, known for its strength and elasticity. - Dacron: This is a polyester, not a polyamide.

Step 3: Select the Correct Answer

Based on the analysis in the previous step, Nylon is the fiber made of polyamides. It fits the definition of a polyamide by containing the amide bond in its repeating units.

Key Concepts

Synthetic Fibers

Synthetic fibers are man-made fibers created through chemical processes rather than by nature. These fibers are usually derived from petrochemicals, offering a wide array of versatile properties that nature-based fibers may not offer. The development of synthetic fibers revolutionized the textile industry and allowed for a greater range of materials with specific desired qualities such as elasticity, strength, and resistance to various environmental factors.

Some key types of synthetic fibers include:

• Polyamides: Known for their durability and strength, commonly found in materials like Nylon.
• Polyester: Widely used for their resistance to wrinkles and shrinking; Dacron is an example.
• Acrylics: Imitates wool; Orlon is a well-known brand.

One of the remarkable aspects of synthetic fibers is their capacity to be engineered for specific uses. This could be anything ranging from clothing and carpets to industrial uses like ropes and parachute cords.

Nylon

Nylon is one of the most prominent types of synthetic fibers. It belongs to the family of polyamides and was first introduced in the 1930s by Wallace Carothers and his team at DuPont. Nylon's invention marked the beginning of a new age of materials science, offering unprecedented qualities such as high strength, elasticity, and abrasion resistance.

Some notable characteristics of nylon include:

• Elasticity: It has remarkable stretchability, making it suitable for activewear and hosiery.
• Durability: Known for its ability to withstand wear and tear, which is why it is often used in outdoor gear.
• Moisture Resistance: Nylon is less absorbent, making it fast-drying, hence preferred for swimwear.

These properties make Nylon an incredibly versatile material used in a multitude of products, ranging from textiles to automotive and industrial applications. Furthermore, nylon can be engineered in various grades and forms, adapting to diverse requirements and purposes.

Amide Bonds

Amide bonds play a crucial role in the structure of polyamide fibers like Nylon. Essentially, an amide bond is a type of covalent bond that forms between a carboxylic acid and an amine. It is characterized by the linkage \[ \text{-CO-NH-} \], which is the backbone of polyamide structures.

The formation of amide bonds in polyamides:

• Chemical Stability: Amide bonds confer high thermal and chemical stability, which contributes to the resistance and longevity of materials made from polyamides.
• Structural Integrity: These bonds provide structural coherence, ensuring that the fibers retain their form and function under various conditions.
• Functionality: The versatility of amide bonds allows for the formation of complex structures necessary for advanced material design.

In the realm of materials science, understanding amide bonds is essential as they underpin the properties that make polyamides indispensable for both everyday and specialized applications.