Question

Which of the following fibers are made by condensation reactions?
A. Acrylic
B. Olefin
C. Cellulose
D. Polyester
Choose the correct answer from the options given below:

• A. A and B only
• B. B and C only
• C. C and D only
• D. A and D only

Hint:

Condensation polymers (like polyester and nylon) eliminate a small molecular by-product (such as water or HCl) during polymerization, whereas addition polymers (like acrylic and olefin) do not.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Polymerization is the chemical process of linking monomer units together to form long macromolecular chains (polymers).
The two primary mechanisms of polymerization are addition (chain-growth) polymerization and condensation (step-growth) polymerization.

Step 2: Detailed Explanation:
Let us analyze the chemical synthesis of the listed fibers:
- Acrylic (A): Composed of polyacrylonitrile, produced via addition polymerization of acrylonitrile monomers. No small molecules are eliminated during this reaction.
- Olefin (B): Composed of polypropylene or polyethylene, produced via addition polymerization of ethylene or propylene monomers.
- Cellulose (C): A natural polymer. Biochemically, plants synthesize cellulose through enzymatic condensation polymerization, where glucose monomers are linked by \(\beta\)-(1\(\rightarrow\)4) glycosidic bonds, eliminating water molecules in the process.
- Polyester (D): A classic synthetic condensation polymer.
It is synthesized by reacting a dicarboxylic acid (e.g., terephthalic acid) with a diol (e.g., ethylene glycol).
This reaction links the ester groups together while eliminating water or alcohol as a by-product.
Therefore, Cellulose and Polyester are formed via condensation reactions, while Acrylic and Olefin are addition polymers.

Step 3: Final Answer:
The fibers made by condensation reactions are Cellulose and Polyester (C and D only).