Polymers Flashcards
what are the repeating units of addition polymers?
monomers
how does addition polymerisation occur
by breaking the double bonds in the unsaturated monomers, and joining them to form a polymer chain
what property makes it important to recycle addition polymers
addition polymers are chemically inert, and so difficult to breakdown. they are non-biodegradeable
what is different about the monomers used to make condensation polymers?
they don’t have a double bond. the monomers dont have to be the same.
give three common types of condensation polymers
polypeptides, polyamides and polyesters (polyamides and polypeptides both have the functional group
-CONH-
name the general name of the two compounds that react under a condensation reaction to form a polyester
a dicarboxylic acid and a diol
give a common example of a polyester
PET
give 2 uses of PET
- used to make fibres to make clothes
- used to make bottles
name the two compounds used to make PET
benzene-1,4-dicarboxylic acid and ethan-1,2-diol
what is the general name given to the two compounds that react to form polyamides
dicarboxylic acids and diamines
give a common example of a polyamide
Kevlar
name the two monomers used to make Kevlar
Benzene-1,4-dicarboxylic acid and Benzene-1,4-diamine
give two uses of Kevlar
- used in bullet proof vests-very strong material
- used in lightweight mountaineering ropes
what monomers are used to make Polypeptides
amino acids react together in a condensation reaction, releasing a water molecule
why can the polymer formed also be called a polyamide
because the amino acid monomers contain a carboxylic group and an amine group
what is formed when concentrated acid is used to break down the polymers
a protonated zwitterion is formed. the acidic condition gives rise to a NH4 group with a positive charge
what is the strongest intermolecular force in addition polymers, and why
the strongest intermolecular is usually van der waals, because they are usually long chain, non polar hydrocarbons
why do the hydrocarbon chains tend to have high melting and boiling points?
because they have a large surface area for many van der waals to act across
what type of bonding is characteristic of condensation polymers
polar bonding
what is the strongest type of intermolecular in polyamides
hydrogen bonding between the H and O
what feature of condensation polymers makes them biodegradeable
they are made up of chains containing polar bonds-polar atoms can be readily attacked by nucleophiles and so the polymers can be broken up and the constituent monomers reformed-hydrolysis
give 2 advantages and disadvantages of recycling polymers
1) less need for resources to be extracted if they are reused
2) less landfill
1) takes time and energy
2) expensive process and changes the property of the plastic
