Polymerisation Flashcards
condensation polymers
dicarboxylic acid + diols –> polymers + water
addition vs condensation polymer
PVC = addition polymer = not biodegradable
PLA = condensation polymer = is biodegradable
C-C bonds
Carbon carbon bonds = strong and non-polar = difficult to break and unreactive
hydrolysis of polyesters etc
Water from air and soil can hydrolyse polyamides and polyesters
why is it biodegrdable
-ester/amide links contain polar C=O bonds that can react with nucelophiles to break the polymer chain
Not biodegradable = non-polar C-C bonds
Single monomer unit = 1 oxygen and 1 carbonyl group
amide
Amide = C=O-N-H
what is required to make a condensation polymer
2 different monomers which each have 2 functional groups
Kevlar
very strong but lightweight
draw the repeating unit =
without the brackets + n
polyester
-dicarboxylic acid + diol
-ester links O=C-O + H2O
-catalysts for condensation polymer = sulfuric acid
naming addition polymers
-naming addition polymers using the monomer e.g polyethene
polyamide
-dicarboxylic acid + diamine
Ethane-1,2,-diol =
HOCH2CH2OH
addition polymer
An addition polymer forms when unsaturated
monomers react to form a polymer
Monomers contain C=C bonds
poly(alkenes)
Poly(alkenes) are chemically inert due to the strong C-C and C-H
bonds and non-polar nature of the bonds and therefore are
non-biodegradable.
example of polyester
terylene
example of polyamide
Kevlar
Nylon 6,6
what is terylene made from
Benzene-1,4-dicarboxylic acid
Ethane-1,2-diol
what is Nylon 6,6 made from
hexanedioic acid
Hexane-1,6-diamine
what is Kevlar made from
diphenylamine
dibenzene carboxylic acid
answering exam questions
If asked for type of polymer: It is polyamide or polyester
Whereas type of polymerisation is condensation
IMF in polymers
Polyesters have permanent dipole forces between the Cδ+=Oδ- groups in the different chains in addition to
the van der waals forces between the chains.
Polyamides (and proteins) have hydrogen bonding
between the oxygen in Cδ+=Oδ- groups and the H in
the Nδ- —Hδ+ groups in the different chains in addition
to the van der waals forces.
Polyamides will therefore have higher melting points
than polyesters.
disposal of polymers
The most common method of disposal of waste in UK
Many are now reaching capacity.
European regulations will mean councils are charged much more for using landfill.
Most polymers (polyalkenes) are non-biodegradable and take many years to break down.
Could use more biodegradable plastics, e.g. Polyamides and cellulose and starch based polymers to improve
rates of decomposition
Incineration
Rubbish is burnt and energy produced is used to generate electricity.
Some toxins can be released on incineration. Modern incinerators can burn more efficiently and most toxins
and pollutants can be removed. Greenhouse gases will still be emitted though.
Volume of rubbish is greatly reduced.
Recycling
Saves raw materials- nearly all polymers are formed from compounds sourced/produced from crude oil. Saves
precious resources.
Polymers need collecting/ sorting- expensive process in terms of energy and manpower.
Polymers can only be recycled into the same type – so careful separation needs to be done.
Thermoplastic polymers can be melted down and reshaped
polyalkanes vs polyamines
-polyalkanes = inert and biodegradable
-polyesters + polyamides = broken down by hydrolysis and are biodegradable t
types of polymers
PVC = CH3Cl
C2F4 = tetraflouroethene
biodegradable
Biodegradable = capable of being decomposed by bacteria or other biological means
-Molecules are biodegradable as they have polar C=O bonds that can be attacked by nucelophiles
why cant polyalkanes by hydrolysed
Polyalkanes cant be hydrolysed = they are unreactive C-C bonds. Cannot be attacked by nucelophiles
incinerate
advantages –>-cheap
-doesn’t take up landfill space
-produces energy (combustion)
Disadvantages –> -produces CO2 emissions
-toxic gases e,g O2
-CO = insufficient oxygen
landfill
advantages –>cheap/easy
-doesn’t produce toxic gases
-biodegradable polymers can decompose
disadvantages –> -eyesore
-transporting watse
-contaminates water
-harms wildelife
-insufficient water for hydrolysis
recycle
advantages –>-saving raw materials (crude oil)
-cheaper than making from raw materials
disadvantages –> breaks carbon chains when molten and reformed
-difficult and expensive
-cause contamination of plastics
repeating unit of polystyrene
(addition polymer)
—–CH2-CH—- with benzene ring connected to CH
