Chapter 26, Problem 26.22P

Interpretation Introduction

(a)

Interpretation:

Which polymer, G or H, has the higher ${\text{T}}_{\text{g}}$ is to be predicted and to be justified.

Concept introduction:

The glass transition temperature ${\text{(T}}_{\text{g}})$ is thermal property that quantifies the crystalline and amorphous character of a polymer. Thermal transitions and the solubility properties of a polymer depend on the length of the polymer molecules, the extent of branching, the rigidity of the polymer, the symmetry of the polymer, and the intermolecular forces.

The regular occurrence of pendant groups along a polymer chain increases ${\text{T}}_{\text{g}}$. Rigid polymer chains have higher ${\text{T}}_{\text{g}}$ than flexible chains.

Interpretation Introduction

(b)

Interpretation:

Which polymer, I or J, has the higher ${\text{T}}_{\text{g}}$ is to be predicted and to be justified.

Concept introduction:

The glass transition temperature ${\text{(T}}_{\text{g}})$ is thermal property that quantifies the crystalline and amorphous character of a polymer. Thermal transitions and the solubility properties of a polymer depend on the length of the polymer molecules, the extent of branching, the rigidity of the polymer, the symmetry of the polymer, and the intermolecular forces.

Pendant groups that extend farther away from the main chain lower ${\text{T}}_{\text{g}}$.