Problem 96 - A Complete Resource Book in Chemistry for JEE Main

Question

Which of the following statements about carbon fibres are correct? (1) They can be made from viscose rayon (2) They are used for making nose tips of missiles (3) They have low thermal conductivity and used as insulators (4) They are used for making components of bone plates Select the correct answer. (a) 1,2 and 3 (b) 2 and 3 only (c) 1,2 and 4 (d) 2 and 4 only

Step-by-Step Solution

Answer

The correct answer is (c) 1, 2 and 4.

Step 1: Evaluate Statement 1

Carbon fibres can indeed be manufactured from a polymer called viscose rayon. This polymer is transformed through a series of steps (including stabilization and carbonization) into carbon fibres, so Statement 1 is correct.

Step 2: Analyze Statement 2

Carbon fibres are known for their high strength-to-weight ratio and ability to withstand high temperatures, making them ideal materials for aerospace applications such as the nose tips of missiles. Thus, Statement 2 is correct.

Step 3: Consider Statement 3

Carbon fibres actually have high thermal conductivity, not low. Instead of being used as insulators, they are used in applications requiring heat dissipation. Therefore, Statement 3 is incorrect.

Step 4: Assess Statement 4

Due to their strength, lightweight, and biocompatibility, carbon fibres are utilized in medical applications, including the manufacture of components for bone plates. Hence, Statement 4 is correct.

Step 5: Conclusion

Based on our evaluation, Statements 1, 2, and 4 are correct. Corresponding to option (c), which lists 1, 2, and 4 as the correct statements, this is the correct choice.

Key Concepts

Polymer Engineering

Polymer engineering is a fascinating field that focuses on the design, analysis, and manufacturing of polymer materials. Polymers are large molecules composed of many repeated subunits, giving them unique properties. One of the key areas within polymer engineering is the transformation of these polymers into useful materials, such as carbon fibres. Carbon fibres are typically made from a precursor polymer like viscose rayon.

• Vicscose rayon undergoes processes like stabilization and carbonization to form carbon fibres.
• These procedures change the polymer's structure to create material with excellent strength and stability.

Polymer engineering not only allows for innovations in materials like carbon fibres but also contributes to a wide range of other fields, enhancing everything from packaging and textiles to medical devices.

Aerospace Materials

In the aerospace industry, materials are required to have specific properties such as strength, lightweight, and heat resistance. Carbon fibres excel in these areas, making them a staple in aerospace engineering.

• This material is often used in high-performance applications like the nose tips of missiles.
• It offers a great strength-to-weight ratio and can withstand extreme temperatures.

These features are critical for the aerospace sector, where performance and safety are paramount. Engineers continuously research and develop new materials to expand the capabilities of aircraft and spacecraft, ensuring improved efficiency and safety.

Biocompatibility

Biocompatibility refers to the property of a material being compatible with living tissue, without causing an adverse reaction. Carbon fibres are known for their biocompatibility, which makes them suitable for medical applications.

• They are used in making components for bone plates and other medical implants due to their compatibility with human tissue.
• Carbon fibres offer the necessary strength and lightweight characteristics required by doctors and surgeons.

This property ensures the material can function effectively within the human body, benefiting medical advancements.

Material Properties

Understanding the various material properties of carbon fibres helps in determining their application across different industries. While carbon fibres are prized for their strength and lightweight, they also possess other significant properties.

• They have high thermal conductivity, making them useful in applications involving heat dissipation rather than insulation.
• Their chemical resistance protects them from corrosion, further extending their application range.

These properties make carbon fibres a versatile choice for many applications, from sports equipment to structural engineering, due to their exceptional durability and performance.