The monomer of terylene are:

A. Phenol and formaldehyde

B. Ethylene glycol and phthalic acid

C. Adipic acid and hexamethylenediamine

D. Ethylene glycol and terephthalic acid

The correct answer to your question about the monomers of terylene is D: Ethylene glycol and terephthalic acid. Terylene, also known as polyethylene terephthalate (PET), is a type of polyester that is widely used in textiles and packaging materials. Let's break down why this is the case and how these monomers contribute to the formation of terylene.

Understanding the Components

Terylene is synthesized through a condensation polymerization process involving two specific monomers:

• Ethylene Glycol: This is a diol, meaning it has two hydroxyl (-OH) groups. Its chemical formula is C2H6O2. Ethylene glycol is a colorless, odorless liquid that is commonly used in antifreeze and as a precursor for producing polyester fibers.
• Terephthalic Acid: This is a dicarboxylic acid with the formula C8H6O4. It contains two carboxyl (-COOH) groups, which are essential for forming the polyester linkage during polymerization.

How They Combine

During the polymerization process, the hydroxyl groups from ethylene glycol react with the carboxyl groups from terephthalic acid. This reaction results in the formation of ester bonds, releasing water as a byproduct. The overall reaction can be summarized as follows:

Ethylene Glycol + Terephthalic Acid → Terylene + Water

This reaction continues, leading to the formation of long chains of terylene, which gives the material its desirable properties such as strength, durability, and resistance to stretching and shrinking.

Why Other Options Are Incorrect

Let’s briefly examine why the other options do not represent the monomers of terylene:

• A. Phenol and formaldehyde: These are the monomers used to create phenolic resins, not terylene.
• B. Ethylene glycol and phthalic acid: While ethylene glycol is correct, phthalic acid is not the same as terephthalic acid, which has an additional -COOH group, making it suitable for terylene synthesis.
• C. Adipic acid and hexamethylenediamine: These monomers are used to produce nylon, specifically nylon 66, not terylene.

Applications of Terylene

Terylene is widely used in various applications due to its excellent properties. It is commonly found in:

• Clothing and textiles, where it provides durability and wrinkle resistance.
• Plastic bottles and containers, thanks to its strength and lightweight nature.
• Films and sheets used in packaging, which benefit from its barrier properties.

In summary, the monomers that make up terylene are indeed ethylene glycol and terephthalic acid, which combine through a condensation reaction to form this versatile polyester. Understanding these components helps appreciate the material's widespread use in everyday products.