6.3.2 - Polyesters and Polyamides Flashcards
What are the two types of polymerisation?
Addition and condensation.
When are addition polymers formed?
By monomers undergoing addition reactions with themselves.
How can alkenes undergo addition polymerisation?
Can be made to join together in the presence of high pressure and a suitable catalyst. The pi bond breaks and the molecules join together to form a long polymer chain.
How many products in addition polymerisation?
Only 1, the polymer.
When are monomers formed by condensation?
From two types of monomers, each of which has at least two functional groups.
What the types of link in condensation polymerisation?
Ester or amide.
What else is produced during condensation polymerisation?
A small molecule is lost, often water or HCl.
What is the ester link?
-COO-
What is the amide link?
-CONH-
When are polyesters formed?
When dicarboxylic acids react with diols.
What can you use to produce a better yield and why?
Acyl chlorides, as they are more reactive than carboxylic acids and therefore polymerisation reactions with acyl chlorides produce a better yield.
Why is polymerisation with acyl chlorides difficult to reverse?
The HCl produced is gaseous and so escapes.
How can condensation polymers be broken down?
Hydrolysis, either acid or base.
In base hydrolysis of polyesters what are the products?
Dialcohol and then the carboxylic acid with O-Na+ group on the C=O group.
In acid hydrolysis of polyesters what is formed?
Dialcohol and dicarboxylic acid.
