Polymers and Esters Flashcards
What’s a polymer?
A polymer is a large molecule made from lots of small molecules, called monomers, joined together.
What’s Polymerisation?
The process in which monomers join together
Can polymer molecules be given a specific relative molecular mass?-why?
No
- Polymer molecules can be different lengths
- But, we know that a polymer has a high AVERAGE relative molecular mass
Explain Addition Polymerisation
One of an alkenes’ double bond breaks open so another alkene molecule adds on
This process occurs again and again, forming a long chain
What’s the repeating unit?
Shows how many groups of atoms that are repeated in the polymer
What do addition polymerisation reactions require?
Pressure and a catalyst
Draw the polymerisation of Butene/what does it form?
See Ipad for answer!! Poly(Butene)
How are polyesters made?
Condensation polymerisation:
- the monomers join together and eliminate a small molecule such as water
What type of polymer are polyesters?
Synthetic polymers
What’s the functional group of Esters?
-COO-
How are esters formed?
A carboxylic acid reacts with an alcohol in the presence of a catalyst
Why is the formation of esters a condensation reaction?
Water is also produced
What do Esters end in?
-ethyl
-noate
What’s Poly(ethene)’s common name and use?
- Polythene
- Plastic bags/cling film
What’s Poly(propene)’s common name and use?
- Polypropylene
- Ropes/carpets
What’s Poly(chloroethene)’s common name and use?
- PVC
- Window frames/covering for electrical wires
What’s Poly(tetrafluoroethene)’s common name and use?
- PTFE
- Non stick coating on frying pans
What’s Poly(phenylethene)’s common name and use?
- Polystyrene
- Packaging/thermal insulation on ceilings
What are the uses for Esters? - why?
Perfumes and food flavourings:
- Pleasant smell
- Volatile (evaporate easily)
Other than the Ester, what product is formed when an alcohol and carboxylic acid react?-why?
Water: Carboxylic acid loses its OH group, and the alcohol loses the hydrogen from its OH group to form a water molecule
How can organic molecules form polymers without an alkene?
Condensation polymerisation
Explain what happens during condensation polymerisation.
- Involves a carboxylic acid and alcohol
- The OH part of the carboxylic acid functional group joins with the hydrogen atom from the alcohol functional group to form a water molecule
- The rest of the carboxylic acid and alcohol molecules join up to form a polymer molecule (-thyl -anoate)
How are polyesters formed?
When carboxylic acids and alcohols have a functional
group at each end of their molecules, they join up to form a polyester and some water molecules.
The monomers are joined together by ester links
How can polyesters with different properties be produced?
-By varying the numbers of carbon atoms in the monomers,
and what is attached to them