Chapter 26, Problem 26.58P

Interpretation Introduction

(a)

Interpretation:

From the given polycarbonate polymers E–G, which one has the highest ${\text{T}}_{\text{g}}$ is to be determined.

Concept introduction:

Polymers that have stronger types of intermolecular interactions generally have a higher ${\text{T}}_{\text{g}}$ and ${\text{T}}_{\text{m}}$. If the polymer has pendant groups that occur regularly, then the Tm will increase because these groups increase the barrier to rotation about single bonds. With less rotation about the main chain, the polymer can more easily arrange itself into a crystal lattice and achieve more extensive intermolecular interactions. The regular occurrence of pendant groups along a polymer chain increases ${\text{T}}_{\text{g}}$ and ${\text{T}}_{\text{m}}$.

Interpretation Introduction

(a)

Interpretation:

From the given polycarbonate polymers E–G, which one has the lowest ${\text{T}}_{\text{g}}$ is to be determined.

Concept introduction:

Polymers that have stronger types of intermolecular interactions generally have a higher ${\text{T}}_{\text{g}}$ and ${\text{T}}_{\text{m}}$. If the polymer has pendant groups that occur regularly, then the Tm will increase because these groups increase the barrier to rotation about single bonds. With less rotation about the main chain, the polymer can more easily arrange itself into a crystal lattice and achieve more extensive intermolecular interactions. The regular occurrence of pendant groups along a polymer chain increases ${\text{T}}_{\text{g}}$ and ${\text{T}}_{\text{m}}$.