Step 1: Understanding the Concept:
Polymerization is the process of combining small monomer molecules to form a large polymer. There are two main types:
1. Addition Polymerization: Monomers with double/triple bonds simply add to each other without losing any atoms.
2. Condensation Polymerization: Monomers with two or more reactive functional groups combine, accompanied by the elimination of a small molecule like water, HCl, or methanol.
Step 2: Key Formula or Approach:
Analyze the monomer units of each given polymer.
If the monomer has a \( \text{C=C} \) double bond, it typically undergoes addition polymerization.
If the monomers have functional groups like \( \text{-OH} \), \( \text{-COOH} \), or \( \text{-NH}_2 \), they typically undergo condensation polymerization.
Step 3: Detailed Explanation:
Let's evaluate each option:
(A) Polythene: Its monomer is ethene (\( \text{CH}_2\text{=CH}_2 \)). It polymerizes via addition polymerization.
\[ n(\text{CH}_2\text{=CH}_2) \rightarrow [-\text{CH}_2\text{-CH}_2-]_n \]
(C) Polyacrylonitrile (PAN): Its monomer is acrylonitrile (\( \text{CH}_2\text{=CH-CN} \)). It polymerizes via addition polymerization.
\[ n(\text{CH}_2\text{=CH-CN}) \rightarrow [-\text{CH}_2\text{-CH(CN)}-]_n \]
(D) Teflon: Its monomer is tetrafluoroethene (\( \text{CF}_2\text{=CF}_2 \)). It polymerizes via addition polymerization.
\[ n(\text{CF}_2\text{=CF}_2) \rightarrow [-\text{CF}_2\text{-CF}_2-]_n \]
(B) Nylon 6,6: It is a polyamide formed by the condensation reaction between two monomers: hexamethylenediamine (\( \text{H}_2\text{N-(CH}_2\text{)}_6\text{-NH}_2 \)) and adipic acid (\( \text{HOOC-(CH}_2\text{)}_4\text{-COOH} \)).
During the reaction, an \( \text{-OH} \) group from the acid and an \( \text{-H} \) from the amine combine to eliminate a water molecule (\( \text{H}_2\text{O} \)), forming an amide linkage.
\[ n\text{HOOC-(CH}_2)_4\text{-COOH} + n\text{H}_2\text{N-(CH}_2)_6\text{-NH}_2 \rightarrow [-\text{OC-(CH}_2)_4\text{-CO-NH-(CH}_2)_6\text{-NH}-]_n + 2n\text{H}_2\text{O} \]
Therefore, Nylon 6,6 is a condensation polymer.
Step 4: Final Answer:
Nylon 6,6 is obtained by the condensation polymerisation method.