Problem 7 - A Complete Resource Book in Chemistry for JEE Main

Question

Which among the following is a synthetic polymer? (a) phenol-formaldehyde resin (b) proteins (c) polysaccharides (d) natural rubber

Step-by-Step Solution

Answer

Phenol-formaldehyde resin is a synthetic polymer.

Step 1: Identify the type of polymers

First, let's identify what a synthetic polymer is. Synthetic polymers are man-made polymers designed and engineered for a variety of purposes, unlike natural polymers, which are found in nature.

Step 2: Analyze the Options

Examine each option to determine whether they are synthetic or natural polymers: (a) Phenol-formaldehyde resin - This is a well-known synthetic polymer made from phenol and formaldehyde. (b) Proteins - Proteins are natural polymers composed of amino acids, found in living organisms. (c) Polysaccharides - These are natural polymers, such as starch or cellulose, composed of sugar units. (d) Natural rubber - As the name suggests, this is a natural polymer produced from the latex of rubber trees.

Step 3: Identify the Synthetic Polymer

Based on the analysis of each option: (a) Phenol-formaldehyde resin is a synthetic polymer, as it is chemically synthesized. (b), (c), and (d) are natural polymers. Therefore, (a) phenol-formaldehyde resin is the synthetic polymer among the listed options.

Key Concepts

Phenol-formaldehyde resin

Phenol-formaldehyde resin is one of the earliest synthetic polymers ever created. This resin is produced through a chemical reaction between phenol and formaldehyde. The process involves controlled heating and the presence of a catalyst to form the resin.

These polymers are known for their high durability and resistance to heat. This makes them particularly useful in applications that require thermal stability. Phenol-formaldehyde resins are commonly used in the creation of molded products, laminated products, and insulation materials.

Additionally, they are utilized in adhesives and coatings, which take advantage of the resin's strong bonding capabilities. The invention of phenol-formaldehyde resins marked a significant milestone in polymer chemistry, paving the way for the development of new synthetic materials with a broad range of functions and applications.

Natural vs Synthetic Polymers

Polymers can be categorized into two main groups: natural and synthetic. Understanding the differences between these two types is crucial for comprehending their vast applications.

Natural polymers are substances produced by living organisms. They include polymers like proteins, which serve as essential building blocks for the body, and polysaccharides, such as starch and cellulose, providing energy and structural support.

Synthetic polymers, on the other hand, are human-made materials designed through polymerization processes. Phenol-formaldehyde resin, for instance, is created using chemical reactions that are carefully controlled to achieve desired properties. These man-made polymers are often used in manufacturing due to their customizable properties.

In summary, while natural polymers are vital for biological functions, synthetic polymers are engineered to fulfill specific needs in various industrial applications.

Examples of Polymers

Polymers are all around us, both in nature and in the materials we create. They can be natural, like those produced by plants and animals, or synthetic, designed and synthesized for specific purposes.

Examples of natural polymers include:

• Proteins: Made up of amino acids, they play key roles in biological functions.
• Polysaccharides: Starches and cellulose serve as energy storage and structural components.
• Natural Rubber: Obtained from the latex of rubber trees, used in elastic and flexible products.

Examples of synthetic polymers are:

• Phenol-formaldehyde resin: A heat-resistant polymer used in electrical insulation and coatings.
• Nylon: Known for its strength and elasticity, it's used in fabrics and ropes.
• PVC (Polyvinyl Chloride): Utilized in pipes, flooring, and other construction materials.

These examples illustrate the diversity and importance of polymers in various aspects of modern life.