4.2.2- Polyesters And Polyamides Flashcards
What are two types of polyester
- Made from one type of monomer with carboxylic acid and alcohol groups
- May from two monomers, one which is a diol and one which is a dicarboxylic acid
What is condensation polymerisation
The joining of two monomers with the elimination of a small molecule such as H2O or HCl
State a use of polyesters and polyamides
Clothing- as they form strong fibres which are resistant to stretching, shrinking and chemical attack.
What are the conditions for hydrolysis
The conditions for hydrolysis are always aqueous acid or aqueous base in the presence of heat (reflux). Aqueous means that water must be present as the water molecule is what breaks the bond
What is a biodegradable polymer
A polymer that breaks down completely into carbon dioxide and water
What is a degradable polymer
A polymer that breaks down into smaller fragments when exposed to light, heat, or moisture.
What do you degradable polymers have a structure similar to
Lactic acid
What are photodegradable plastics
Synthetic polymers designed to be to become weak and brittle when exposed to light for prolonged periods
How can photodegradable plastics be manufactured, and what happens to them after they have broken down
- By incorporating carbonyl bonds (C=O) into the backbone of the polymer. The Spartans absorb light energy into break, fracturing the chain.
- By blending light sensitive additives in which catalyse breakdown in the presence of UV radiation
Eventually the polymers are converted to CO2 and H2O in the presence of bacteria
How can condensation polymers breakdown (not photodegradable polymers)
They can be biodegradable by hydrolysis at the ester or amide group
