M7 Polymers Flashcards
How are polymers made
polymerisation
what are the steps of polymerisation
Initiation
Propagation
Termination
what happens during initiation
when diomer splits into two radicals (molecules that have have unpaired electrons)
what happens during propagation
the radical monomer reacts with a monomer, creating a radical polymer, causing a chain reaction
what happens during termination
the radical polymer reacts with the a radical monomer, stopping the chain reaction
what types of polymers are there (2)
- Addition
- Condensation
what are additions polymers
a polymer made from monomers containing a double bond
list examples of addition polymers (4)
- (LDPE) Low Density Polyethylene
- (HDPE) High Density Polyethylene
- (PVC) Polyvinyl Chloride
- polystyrene
what monomer is used in the polymerisation of (LDPE) Low Density Polyethylene
ethylene (Ethene)
what is the structure of (LDPE) Low Density Polyethylene (3) and draw it
Has ethylene branches due to back biting polymer chains can not stack as densely dispersion forces between adjacent chains aren't as effective H H ︱ ︱ (-C-C-)ₙ ︱ ︱ H CH3
what properties does the structure of (LDPE) Low Density Polyethylene give (3)
Flexible
Soft
Low density
what uses does the properties of (LDPE) Low Density Polyethylene give (3)
Wrapping materials
Squeeze bottles
Plastic grocery bags (soft plastic)
what monomer is used in the polymerisation of (HDPE) High density polyethylene and draw it
Ethylene(ethene) ( see polymer table)
what is the structure of (HDPE) High density polyethylene (3)
Straight chains of carbon atoms
Molecules pack closely
Stronger dispersion forces between adjacent molecules
what properties does the structure of (HDPE) High density polyethylene give
High melting point
High density
Hard