Question

The crystallization of a polymer can only proceed in a temperature range limited to glass transition temperature (\(T_g\)) on the lower side and the equilibrium melting point (\(T_m^0\)) on the higher side. In a miscible polymer blend with only one component being crystalline, which option(s) correctly match(es) the Temperature conditions with Events? \[ \begin{array}{|c|c|} \hline \text{Temperature conditions} & \text{Events}
\hline P: T_g \text{ of amorphous component<crystallizable one} & 1: \text{Temperature range for crystallization becomes smaller}
Q: T_g \text{ of amorphous component>crystallizable one} & 2: \text{Crystallization is inhibited}
R: T_g \text{ of blend>} T_m^0 \text{ of crystallizable one} & 3: \text{Crystallization envelope (}T_m^0 - T_g\text{) is widened}
& 4: \text{Crystallization is favored}
\hline \end{array} \]

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

Hint:

Crystallization requires mobility and temperature window (\(T_m^0 - T_g\)). Lower \(T_g\) favors crystallization, higher \(T_g\) reduces the window, and \(T_g>T_m^0\) stops it.

Answer 1

The Correct Option is B, D

Step 1: Condition P.
- If \(T_g\) of amorphous part is lower, mobility is high.
- This favors crystallization. \(\Rightarrow P-4\).

Step 2: Condition Q.
- If \(T_g\) of amorphous part is higher, mobility reduces early.
- This narrows the crystallization temperature window. \(\Rightarrow Q-1\).

Step 3: Condition R.
- If blend \(T_g\) exceeds \(T_m^0\), crystallization is impossible. \(\Rightarrow R-2\).

Step 4: Combine mapping.
\[ P-4, \; Q-1, \; R-2 \] Final Answer: \[ \boxed{\text{(D) P-4; Q-1; R-2}} \]