Question

Which of the following is an example of a condensation polymer?

• A. Polyethylene
• B. PVC
• C. Nylon 6,6
• D. Polystyrene

Hint:

Check how each polymer forms: addition polymers come from monomers with a double bond joining without any by-product, while condensation polymers form when monomers combine with repeated loss of a small molecule like water, giving ester or amide links.

Answer 1

The Correct Option is C

Concept: Polymers are classified mainly into two types based on the mechanism of polymerization:
• Addition polymers: formed by addition of monomers without elimination of small molecules.
• Condensation polymers: formed by the condensation of monomers with the elimination of small molecules such as water or HCl.

Step 1: Identify polymers formed by condensation reaction. Condensation polymers are formed when two different monomers react and release small molecules like water.

Step 2: Formation of Nylon 6,6. Nylon 6,6 is produced by the condensation reaction between: \[ \text{Adipic acid} + \text{Hexamethylenediamine} \] During polymer formation, water molecules are eliminated.

Step 3: Conclusion. Since Nylon 6,6 forms with the elimination of water molecules, it is a condensation polymer.

Answer 2

Concept:

• Condensation polymers form by step-growth polymerisation, where monomers join through repeated loss of a small molecule such as water, producing linkages like ester (-COO-) or amide (-CONH-) between units.
• Addition polymers form by chain-growth polymerisation of monomers containing a carbon-carbon double bond, with no small molecule lost, giving a simple long carbon chain backbone.
• Checking the type of linkage or the presence of a double-bond monomer in each option classifies all four choices at once.

Step 1: Classify Polyethylene.
Formed from ethylene ($CH_2=CH_2$) by addition polymerisation, backbone is plain $-CH_2-CH_2-$, no small molecule lost. Addition polymer.

Step 2: Classify PVC and Polystyrene.
PVC forms from vinyl chloride ($CH_2=CHCl$) and Polystyrene from styrene ($C_6H_5CH=CH_2$), both by addition polymerisation of a double-bond monomer. Both are addition polymers.

Step 3: Classify Nylon 6,6.
Formed from adipic acid and hexamethylenediamine, which join through amide linkages ($-CONH-$) with elimination of water at every step. This is step-growth polymerisation. Condensation polymer.

Final Answer: Nylon 6,6 is the condensation polymer.