Unit 3.4.9 - Polymers Flashcards
What are the two types of polymers?
Addition and condensation
What are addition polymers?
Long chains of monomers formed by breaking double bonds in alkenes and then joining them all together
What is a repeating unit?
The section in a polymer that repeats
What is the difference between the repeating unit and the monomer that makes up a polymer in an addition polymer?
The repeating unit is the monomer without the double bond
What are condensation polymers?
Long chains of monomers that contain at least two functional groups, a molecule of H₂O is released when each monomer is joined
Name three common types of condemnation polymers.
Polyamides, polyesters and polypeptides
What monomers are polyamides made from?
Dicarboxylic acids and diamines
What sort of links are there in polyamides?
Amide links
Name two polyamides.
Nylon 6,6 and Kevlar
What two monomers make up Nylon 6,6?
1,6 diaminohexane and hexanedioic acid
What two monomer make up Kevlar?
benzene-1,4-dicarboxylic acid and benzene-1,4-diamine
What monomers are polyesters made from?
Dicarboxylic acid and Diol
What sort of links are there in polyesters?
Ester links
Name one polyester.
Terylene
What two monomers make up Terylene?
1,4-dicarboxylic acid and ethane-1,2-diol
Why are synthetic polymers widespread?
Because they have lots of advantages
Are condensation polymers or addition polymers very unreactive?
Addition
Why are addition polymers unreactive?
Because the bonds between the repeating units are non-polar so they aren’t susceptible to attack by nuclophiles
Why is it an advantage that addition polymers are unreactive?
They won’t react with what ever they are used for it
What is a disadvantages of addition polymers?
They are non-biodegradable as the bonds in the polymers can’t be hydrolysed and won’t break down easily
Why can condensation polymers be broken down by hydrolysis?
The bonds between the repeating units are polar and so are susceptible to attack by nucleophiles like water
What is an advantage of condensation polymers?
They are bio-degradable and easily broken down
What are the four options four what to do with waste plastics?
Burying, burning, sorting for reusing or sorting for recycling
What does burying waste plastics involve?
Taking them to landfill
When is burying waste plastics usually used?
Generally used when the plastic is difficult to separate from other waste this could be because there isn’t sufficient quantities to make separation financially worthwhile or too difficult to technically recycle
What are two advantages of burying waste plastics?
1.) relatively cheap 2.) easy method to use
What are three disadvantages of burying waste plastics?
1.) It requires areas of land 2.) As the waste decomposes it releases methane - a greenhouse gas 3.) Leaks from landfill sites can contaminate water supplies
Why is there a need to reduce landfill use?
The amount of waste we generate is increasing so it is becoming more and more of a problem
Why does burning waste plastic have to be carefully controlled?
To reduce toxic gases that are released
What is an example of a toxic gas that is removed after burning plastics?
HCl has to be removed when PVC is burned
How are toxic gases removed when you burn waste plastics?
The gases are passed through scrubbers which can neutralise gases by allowing them to react with a base
Which gas don’t scrubbers remove?
CO₂
How do your recycle or reuse plastics?
Plastics are first sorted into different types of plastics Then some are melted and remoulded into something new Where as others are cracked into monomers which can be used to make more plastics or chemicals
Why are plastic products usually marked?
To make sorting easier
What are four advantages of recycling and reusing waste plastics?
1.) Reduces the amount of waste sent to landfills 2.) It saves raw materials - oil is non renewable 3.) The cost of recycling plastic is lower than making the plastics from scratch 4.) It produces less CO₂ emissions than burning the plastic
What are four disadvantages of recycling and reusing waste plastics?
1.) It is technically difficulty to recycle plastics 2.) Collecting, sorting and processing the plastics is more expensive than burning/landfill 3.) You often can’t remake the plastic you started with 4.) The plastic can be easily contaminated during the recycling process
Draw the general reaction for the formation of a polyester.
Draw the general reaction for the foramtion of a polyamide.
Draw the equation for the formation of Kevlar.
Draw the equation for the formation of Terylene.
Draw the eqation for the formation of Nylon 6,6.
