Problem 38 - A Complete Resource Book in Chemistry for JEE Main

Question

Synthetic human hair wigs are made from a copolymer of vinyl chloride and acrylonitrile and is called (a) Dynel (b) Cellulose (c) PVC (d) Polyacrylonitrile

Step-by-Step Solution

Answer

The synthetic polymer used is Dynel (a).

Step 1: Understanding the Options

First, let's review the options provided in the question. We have four different materials listed: (a) Dynel, (b) Cellulose, (c) PVC (Polyvinyl Chloride), and (d) Polyacrylonitrile. These are materials known for their unique properties and uses in synthetic fibers and other applications.

Step 2: Analyzing the Correct Option for Synthetic Hair Wigs

Synthetic human hair wigs are usually made from fibers that can mimic human hair's appearance and feel. Dynel is a type of fiber that is made from a copolymer of vinyl chloride and acrylonitrile, known for its use in synthetic hair. Meanwhile, cellulose, PVC, and polyacrylonitrile are used in other contexts.

Step 3: Matching Copolymer with the Formula

The question mentions a copolymer of vinyl chloride and acrylonitrile. Dynel is a known copolymer of these two components. Polyvinyl chloride (PVC) is made only from vinyl chloride while polyacrylonitrile is made only from acrylonitrile. Cellulose is not related to these compounds.

Key Concepts

Copolymers

Copolymers are a fascinating part of polymer chemistry. They are polymers made from two or more different types of monomers. By combining different monomers, copolymers acquire distinct properties that are not possible with homopolymers, which are polymers made from a single type of monomer.

Imagine copolymers as a team of unique individuals coming together to create something special. In the world of materials, this blending allows for enhanced functionality and a broader range of applications. For example, by copolymerizing vinyl chloride and acrylonitrile, as seen in Dynel fibers, the resulting copolymer can mimic the properties of human hair in synthetic wigs.

Key to understanding copolymers is the fact that the arrangement and proportion of monomers can lead to varied structures such as random, alternating, block, or graft copolymers. Each of these structures results in different material characteristics.

Vinyl Chloride

Vinyl chloride is a crucial ingredient in creating many synthetic materials. It appears as a colorless gas with a slightly sweet odor. In the world of polymers, it is predominantly known for forming Polyvinyl Chloride (PVC), a versatile plastic used in a host of applications, from pipes to clothing.

However, when used in copolymers like with acrylonitrile, it imparts different properties. As part of the copolymer making Dynel, vinyl chloride provides toughness and durability. This is essential in making synthetic hair fibers that can withstand everyday wear and tear.

Importantly, due to its reactive nature, vinyl chloride needs to be handled with care in manufacturing processes. Safety protocols are crucial when dealing with it in its raw form to prevent health hazards.

Acrylonitrile

Acrylonitrile is another player in the synthetic polymer field, known for its strength and resistance to chemicals. This liquid monomer has a pungent odor and is often polymerized to produce materials used in high-performance applications.

In the formation of copolymers like Dynel, acrylonitrile contributes its resistance to loss of shape and fading, making it ideal for synthetic hair wigs. This ensures that wigs can maintain their look and feel over time.

Outside of copolymers, acrylonitrile is also used to create polyacrylonitrile, a homopolymer known for its use in carbon fiber production. Its versatility underscores its importance in developing high-quality, durable synthetic materials.