7. Addition Polymerisation

What are polymers?

very large molecules made when many small molecules caused monomers, joined together by strong covalent bonds to form long chains

How are polymers named?

poly(chloroethene): poly means polymer, the word in the bracket is the same as the monomer it was named

What is addition polymerisation?

where many small monomers react together to make a very large molecule (polymer)

What kind of hydrocarbon can addition polymerisation happen with?

it can only happen with alkenes because it needs a carbon carbon double bond

What is a LDPE?

low density polyethene

What is HDPE?

high density polyethene

What is the structure like in an LDPE?

branching chains make plastics light, soft and easy to melt since the intermolecular forces are weak and are easier to melt

What is the structure like in an HDPE?

lined up chains make plastics dense, rigid and harder to melt since the intermolecular forces are strong and are harder to melt

How are LPDE’s formed?

How are HPDE’s formed?

What are LPDE’s used for?

used for clingfilm and plastic

What are HPDE’s used for?

used for bottles and plastic bags

What are thermosetting and thermosoftening polymers?

types of polymers with different properties

What is the structure of a thermosetting polymer?

rigid structure with fixed chains

What is the structure of a thermosoftening polymer?

long straight chains that are all tangled

What are the bonds like in a thermosetting polymer?

strong, covalent bonds link chains together when heated

What are the bonds like in a thermosoftening polymer?

weak intermolecular bonds that are easily broken with heat

How does thermosetting polymers deal with heat?

they do not soften when heated, just burn

How does thermosoftening polymers deal with heat?

softened with heat and can be remoulded

Are thermosetting polymers recycleable?

no

Are thermosoftening polymers recycleable?

yes

What are thermosetting polymers used for?

where heat resistance is required (kettles, plug sockets)

What are thermosoftening polymers used for?

where heat resistance is not required (carrier bags, bottles)