C11 Polymers Flashcards
How can different forms of poly(ethene) be produced from ethene?
Different Reaction Conditions
Polyesters are produced when monomers join together and lose a small molecule.
Name the small molecule lost.
Water (H2O)
How are synthetic polymers made?
By using alkenes in Addition Polymerisation
What is the atom economy in Addition Polymerisation?
100%
What is addition polymerisation?
The joining of monomers to make polymers
What is a monomer?
A small molecule
What is a polymer?
Large molecules
Give two examples of polymers made by ethene.
Low Density Poly(ethene)
High Density Poly(ethene)
Why does HDPE have a high density?
The molecules are closely packed
There are no branches or side chains
What conditions are needed to make HDPE?
Catalyst
50°C
Slight Pressure
Why does LDPE have a low density?
Less dense
Had side chains and branches
What are the conditions needed to make LDPE?
Trace of oxygen
Moderate Temperature
Very high pressure
What are thermosoftening polymers?
Polymers that melt when they are heated
What are thermosetting polymers?
Polymers that don’t melt when they are heated
Why are thermosoftening polymers have low melting points?
They have individual chains that are entwined with each other with weak intermolecular forces holding the chains together. These are relatively easy to seperate.