Question:
What is the correct order of decreasing crystallinity of the given polymers?
P Atactic–Polypropylene
Q Syndiotactic–Polystyrene
R Nylon6
S Polyethylene terephthalate (PET)
What is the correct order of decreasing crystallinity of the given polymers?
P Atactic–Polypropylene
Q Syndiotactic–Polystyrene
R Nylon6
S Polyethylene terephthalate (PET)
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Tacticity strongly affects crystallinity: \textbf{isotactic > syndiotactic $\gg$ atactic}. Also, strong H-bonding (like in Nylons) enhances crystallinity.
Updated On: Aug 29, 2025
- P > R > S > Q
- S > Q > P > R
- Q > S > R > P
- S > R > Q > P
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The Correct Option is D
Solution and Explanation
Step 1: Atactic polypropylene (P).
Atactic PP has random substituent placement, leading to amorphous structure and negligible crystallinity.
Step 2: Syndiotactic polystyrene (Q).
Syndiotactic PS has an alternating configuration, making it capable of crystallizing (up to $\sim$30–40%).
Step 3: Nylon 6 (R).
Nylon 6 is a semicrystalline polyamide with strong hydrogen bonding between chains, giving high crystallinity (60–70%).
Step 4: Polyethylene terephthalate (S).
PET can reach very high crystallinity (up to 70–80%) under controlled cooling/annealing.
Step 5: Order them.
Thus, decreasing crystallinity: PET (S) > Nylon 6 (R) > Syndiotactic PS (Q) > Atactic PP (P). Final Answer: \[ \boxed{S>R>Q>P} \]
Atactic PP has random substituent placement, leading to amorphous structure and negligible crystallinity.
Step 2: Syndiotactic polystyrene (Q).
Syndiotactic PS has an alternating configuration, making it capable of crystallizing (up to $\sim$30–40%).
Step 3: Nylon 6 (R).
Nylon 6 is a semicrystalline polyamide with strong hydrogen bonding between chains, giving high crystallinity (60–70%).
Step 4: Polyethylene terephthalate (S).
PET can reach very high crystallinity (up to 70–80%) under controlled cooling/annealing.
Step 5: Order them.
Thus, decreasing crystallinity: PET (S) > Nylon 6 (R) > Syndiotactic PS (Q) > Atactic PP (P). Final Answer: \[ \boxed{S>R>Q>P} \]
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