Question

Among the options given, identify the correct match between the polymers and their glass transition temperatures ($T_g$).

• A. P-2; Q-4; R-3; S-1
• B. P-3; Q-1; R-4; S-2
• C. P-3; Q-4; R-1; S-2
• D. P-4; Q-2; R-1; S-3

Hint:

Remember approximate $T_g$ values: HDPE ($\sim$–100 °C), PMMA ($\sim$105 °C), PC ($\sim$150 °C), PVCz (>200 °C).

Answer 1

The Correct Option is B

Step 1: High density polyethylene (P).
HDPE is a semicrystalline polyolefin with very flexible chains. Its $T_g$ lies around –100 to –80 °C. $\Rightarrow P \to 3$.
Step 2: Poly(vinyl carbazole) (Q).
This is an aromatic, rigid side-chain polymer with very high $T_g$ (>200 °C). $\Rightarrow Q \to 1$.
Step 3: Polymethyl methacrylate (R).
PMMA has a $T_g$ around 105 °C. $\Rightarrow R \to 4$ (90–100 °C).
Step 4: Polycarbonate (S).
Polycarbonate has a $T_g$ about 150 °C. $\Rightarrow S \to 2$ (145–155 °C).

Step 5: Conclude.
Thus, the mapping is $P \to 3,\; Q \to 1,\; R \to 4,\; S \to 2$, which matches option (B). Final Answer: \[ \boxed{P\!-\!3;\; Q\!-\!1;\; R\!-\!4;\; S\!-\!2} \]