Polymer Solutions

The immiscible blends exhibit_______

• Excellent mechanical properties

• Poor mechanical properties

• Poor chemical properties

• Intermediate chemical properties

1.       For amorphous and semi-crystalline polymers, mixing leads to the formation of____

• Mechanical blends

• Solution-cast blends

• Solution-cast blends

• Chemical blends

Polymers are dissolved in common solvent to give

• Chemical blends

• Latex blends

• Solution-cast blends

• Mechanical blends

1.       The physical mixture of two or more polymers that are not linked by covalent bonds is called

• Polymerisation

• Dendrimer

• Polyblend

• Multiblend

What is the thermodynamic relation frequently used by chemists to determine if a reaction will be spontaneous?

• The Boltzmann Relation

• The Gibbs free energy equation

• The First Law of Thermodynamics

• Go ask Jerry Falwell

1.       Are most blends of polymers miscible in the absence of strong interactions, such as hydrogen bonds?

• Yes

• No

Why are most blends of polymers immiscible?

• The enthalpy of mixing two polymers is often a large, positive number

• There is a large decrease in the entropy of the system

• There is a very little entropy gained by mixing two polymers and they often have a positive enthalpy of mixing

• The ghost of Paul Flory hates miscible blends and makes most of them immiscible

What USUALLY happens to the mechanical and optical properties of a polymer blend if the components show a significant degree of immiscibility and there is no compatibilizer?

• The properties display a synergistic increase

• The properties are often poor

• Phase separation does not affect these properties

There are several methods of measuring the glass transition(s) of a polymer blend, such as DSC and DMA. How many glass transitions would you expect to see in two component miscible polymer blend? How many glass transitions would you expect to see in a two component immiscible blend (with significant phase separation)?

• One broad glass transition in the miscible blend and two glass transitions in an immiscible blend

• One broad glass transition in the immiscible blend and two glass transitions in an miscible blend

• Two glass transitions, regardless of whether there was phase separation or not