Question:
Among the options given, which method(s) is/are used for the synthesis of atactic polystyrene?
Among the options given, which method(s) is/are used for the synthesis of atactic polystyrene?
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Remember: \textbf{Atactic polystyrene = free radical process}, \textbf{stereoregular polystyrene = Ziegler–Natta or ionic polymerization}.
Updated On: Aug 29, 2025
- Free radical polymerization
- Ring opening polymerization
- Polycondensation
- Ionic polymerization
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The Correct Option is A, D
Solution and Explanation
Step 1: Recall stereoregularity of polystyrene.
Polystyrene can be atactic, syndiotactic, or isotactic depending on how phenyl groups are arranged relative to the chain.
Step 2: Free radical polymerization.
This process proceeds through random attack on styrene monomers, giving no stereocontrol. The result is an atactic polymer, which is amorphous.
Step 3: Rule out others.
- Ring opening polymerization: not applicable to styrene (not a cyclic monomer).
- Polycondensation: not applicable since styrene polymerizes via addition.
- Ionic polymerization (anionic/cationic): may yield syndiotactic or isotactic structures if catalysts/conditions are controlled, but not atactic.
Step 4: Conclude.
Thus, free radical polymerization is the method for atactic polystyrene. Final Answer: \[ \boxed{\text{Free radical polymerization (A)}} \]
Polystyrene can be atactic, syndiotactic, or isotactic depending on how phenyl groups are arranged relative to the chain.
Step 2: Free radical polymerization.
This process proceeds through random attack on styrene monomers, giving no stereocontrol. The result is an atactic polymer, which is amorphous.
Step 3: Rule out others.
- Ring opening polymerization: not applicable to styrene (not a cyclic monomer).
- Polycondensation: not applicable since styrene polymerizes via addition.
- Ionic polymerization (anionic/cationic): may yield syndiotactic or isotactic structures if catalysts/conditions are controlled, but not atactic.
Step 4: Conclude.
Thus, free radical polymerization is the method for atactic polystyrene. Final Answer: \[ \boxed{\text{Free radical polymerization (A)}} \]
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