Problem 5 - Arihant Objective Approach to Organic Chemistry for IIT JEE and NEET all Medical Entrances Part 4

Question

\(\mathrm{CF}_{2}=\mathrm{CF}_{2}\) is a monomer of : \(\quad\) (a) buna-S (b) teflon (c) glyptal (d) nylon-6

Step-by-Step Solution

Answer

(b) Teflon

Step 1: Understand the Terminology

The exercise involves determining which polymer the monomer \( \mathrm{CF}_2 \) belongs to. These are parts of larger molecules that repeat to form a polymer. We need to find which given polymer is made up of this repeating unit.

Step 2: Analyze the Monomer

The molecule \( \mathrm{CF}_2 \) represents a repeating unit consisting of carbon and fluorine. It is a constituent of a specific type of polymer known for its chemical resistance and non-stick properties.

Step 3: Identify the Polymer

The monomer \( \mathrm{CF}_2 \) is actually associated with Teflon, a well-known polymer that is made from the polymerization of \( \mathrm{CF}_2 = \mathrm{CF}_2 \), known as tetrafluoroethylene.

Step 4: Match to Given Options

Compare with the options: (a) buna-S - synthetic rubber, (c) glyptal - used in paints, (d) nylon-6 - a type of polyamide. Option (b) is Teflon, which matches the structure and applications described.

Step 5: Conclusion

Based on the analysis, the monomer \( \mathrm{CF}_2 = \mathrm{CF}_2 \) forms Teflon, thereby making option (b) the correct answer.

Key Concepts

Monomer

In the fascinating world of chemistry, a monomer is like a building block. These small molecules act as the fundamental units that connect together to form larger structures called polymers. Think of a monomer as a single bead in a necklace. When you link these beads together, you create a complete accessory, much like how monomers join to form polymers.

This connection happens through a process called polymerization, where the monomers typically have double bonds or functional groups that allow them to join easily with one another. In our specific example, the monomer is part of a molecule represented by \( \text{CF}_2 = \text{CF}_2 \). This particular monomer is composed of carbon and fluorine atoms. It's the repeating unit that eventually builds up to form the well-known polymer, Teflon.

Monomers are everywhere around us, as they are the starting points for many materials like plastics, fibers, and even the proteins in our bodies. Understanding monomers is vital because they determine the properties and functions of the resulting polymers.

Polymerization

Polymerization is the magical process that transforms simple monomers into complex polymers. Imagine lots of beads stringing together seamlessly to form a necklace. Unlike a simple thread, however, polymerization involves a chemical reaction where monomers link to form long chains.

There are different types of polymerization processes, such as chain-growth and step-growth polymerizations. But in the case of Teflon, as mentioned in our exercise, we're looking at chain-growth polymerization. Here's how it works:

• Initiation: The reaction begins with an initiator that opens the double bonds in the monomer.
• Propagation: The opened bonds allow for new monomers to attach, extending the chain.
• Termination: Once all the monomers have been added or a reaction inhibitor is introduced, the chain stops growing.

This entire process is crucial in producing polymers that have specific characteristics, like Teflon's non-stick and chemical resistance properties. By knowing how polymerization works, we gain insights into the incredible versatility and applications of different polymers.

Tetrafluoroethylene

Tetrafluoroethylene, with the chemical structure \( \mathrm{CF}_2 = \mathrm{CF}_2 \), is the small but mighty monomer we are discussing. It plays a significant role in creating Teflon through the polymerization process.

What makes tetrafluoroethylene special? It contains carbon and fluorine atoms, where the strong bonds between them contribute to the unique properties of Teflon. Here are some fascinating aspects of tetrafluoroethylene:

• Chemical Resistance: The strength of the carbon-fluorine bonds makes the resulting polymer resistant to a wide array of chemicals.
• Non-stick Nature: This same bond strength and the polymer's smooth surface reduce friction, leading to Teflon's famous non-stick property.
• Heat Resistance: Tetrafluoroethylene-based polymers can withstand high temperatures without degrading, making them ideal for various high-heat applications.

Understanding tetrafluoroethylene gives us the ability to appreciate how versatile and useful the polymers derived from it, like Teflon, are in our everyday lives. From non-stick frying pans to protective clothing, the legacy of this small molecule is indeed vast.