CONDENSATION POLYMERS Flashcards
Condensation polymers
compised of 3 main types : polypeptides, polyamides and polyesters.
condensation polymerisation
2 different monomers with atleast 2 functional groups are joined together. where they react a link is made and water is eliminated, hence condensation polymerisation.
types of polymers
- polypeptides - found in proteins
- polyamides - formed by reacting diamines and dicarboxylic acids
- poly esters - formed by reacting diol and dicarboxylic acid together.
poly amides
- dicarboxylic acids reacting with di amines.
- using dicarbolic acids and diamines as tthey have functional group on either side allowing for chains to be formed.
kevlar
kevlar is a polyamide used in bullet proof vests, car tyres and sport equipments as it is light weight but strong
what is kevlar made of
benzene 1 - 4 dicarboxylic acid and 1,4 - diamino benzene.
nylon
nylon 6,6 isa polyamide used in ropes, carpets , clothing and parachute fabric.
what is nylon 6,6 made of
hexane dioic acid and 1,6 - diamino hexane
polyesters
formed by reacting dicarboxylic acids and diols together.
what is formed when dicarboxylic acids react with diols
ester links
terylene
terylene is a poly ester used in plastic drink bottle, sheeting and clothes. has the acronym PET
what is terylene made of
benzene - 1,4 dicarboxylic acid and ethane - 1,2 diol.
hydrolysis
condensation polymers can be hydrolysed to produce original monomers. reverse of polymerisation.
polarity in condensation polymers
condensation polymers have polar bonds caused by C - O and C-N bonds in polymers.
hydrogen bonds exist between polymer chains, as well as dipole dipole and vanderwaals forces which makes the condensation polymers more strong than additonal polymers.
condensation polymer polarity
- ## usually more rigid and stronger than addition polymer counter parts.
why are condensation polymers stronger than addition polymers?
hydrogen bonds exist beyween polymer chains as well as dipole dipole and vander waals force making condensation polymers stronger than addition polymers.
uses of polymers
- synthetic polymers made from monomer units used to make a range of items like plastic bottles, digital technology to non stick coating on pans.
- condensation polymers like polyamides and poly esters are polar and are suspectible to attack from nucleophiles, hence they are bio degradable and broken by hydrolysis.
- poly alkenes such a spoly ethene are saturated molecule, non polar and good for foods because they dont react with food.
why are polyesters and poly amides broken down
- because they are polar
- suspectible to be attacked by nucleophiles.
- hence they are bio degredabale and hydrolysed.
why are polyalkenes not degradable
- example of addition polymer
- saturated molecules, usually non polar and hence unreactive.
- good when used in foods as they dont react but bad for landfill as they dont degrade.
disposal of plastics
most polymers are non biodegradable so proper disposal is very necesary.
what kind of plastics are disposed in landfill?
- plastics that are too difficult to recycle
- plastics that are difficult to separate from other materials
- not enough plastic to extract to make it economically viable.
what gas is produced when plastics decomposes in landfill
- methane which is a greenhouse gas
- there is also an increased risk of water contamination from waste leaching.
incineration
burning waste plastics which cannot be recycled .
- energy from burning can be used to generate electricity.
what does burning plastics releases
toxic fumes
- specially chlorine based plastics like pvc produces harmful hcl when burned.
- flue gas scrubbers are used to neutralise acidic gases like hcl.
