List of top Polymer Science and Engineering Questions on Polymer crystallinity asked in GATE XE

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? \[ \begin{array}{|c|c|} \hline \text{Temperature conditions} & \text{Events}
\hline P: T_g \text{ of amorphous component<crystallizable one} & 1: \text{Temperature range for crystallization becomes smaller}
Q: T_g \text{ of amorphous component>crystallizable one} & 2: \text{Crystallization is inhibited}
R: T_g \text{ of blend>} T_m^0 \text{ of crystallizable one} & 3: \text{Crystallization envelope (}T_m^0 - T_g\text{) is widened}
& 4: \text{Crystallization is favored}
\hline \end{array} \]

The density of an amorphous polymer is 0.77 g/cm\(^3\) and that of its crystalline counterpart is 0.99 g/cm\(^3\). The density of a semi-crystalline sample of this polymer is 0.88 g/cm\(^3\). Find the degree of crystallinity (on weight basis) of this semi-crystalline sample. (Round off to two decimal places)

Crystallization is favored in polymer melts when the chain entanglement is ............ and only polymers with .................. molecular arrangement can crystallize.

A nylon sample of 0.03 m$^2$ cross-sectional area is subjected to a creep load of 10 kN. The load is removed after a duration of 60 s. Young’s modulus and the viscosity for nylon are 1 GPa and 300 Giga Poise. The compliance of the specimen is ______ $\times 10^{-9}$ m$^2$/N.

Density = 0.9 g/cc, melt volume = 10 cc, residence time = 100 s. Find extruder output in kg/h.

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