5.7 Polymer Properties by Design 1 Flashcards
What are polymers formed from condensation reactions called?
Condensation polymers.
What does the monomer need for a condensation polymer to be produced?
At least two suitable functional groups per molecule for a condensation polymer to be produced.
What is a condensation reaction?
When two monomers join together to form a longer chain polymer and a small stable molecule, usually a water or hydrogen chloride.
What is Terylene known as?
A polyester.
How are polyesters formed?
Alcohol+ Carboxylic Acid.
What are Nylon and Terylene both ideal for?
As fibres.
What happens when polymers are cooled
They become brittle or glassy.
What happens when polymers are heated
They become flexible before melting.
What type of regions are present in a polymer?
there are areas of crystalline (ordered) and amorphous regions (random)
In a glassy state what happens to the amporhous regions?
Amorphous regions are frozen so that easy movement of chains is not possible.
Do not have enough energy to overcome the intermolecular forces.
When the polymer is a glassy state, if it is forced to change shape what happens?
If the polymer is forced to change shape, it does so by breaking.
When glassy material is heated what happens? What are the properties?
the polymer chains will reach a temperature at which they can move relative to each other (the glass transition temperature Tg).
What happens upon further heating of the polymer after Tg
Further heating of the glassy polymer, it becomes flexible and shows the more conventional properties expected of a plastic.
What happens upon FURTHER FURTHER FUTHER heating?
The melting temperature (Tm) is reached
What happens to the crystalline areas?
The crystalline areas break down and the polymer becomes a viscous fluid.
