Section 7 - Polymers Flashcards
What are 3 examples of condensation polymers?
- polyamides
- polyesters
- polypeptides
What is a condensation polymer?
Two different types of monomer, each with at least two functional groups, which form a link.
Why are condensation polymers called that?
Every time a link is formed, a molecule of water is lost.
What do reactions between dicarboxylic acids and diamines make?
Polyamides
What is Nylon 6,6 made from?
1,6-diaminohexane and hexadioic acid.
What is nylon 6,6 used to make?
- clothing
- carpet
- rope
- airbags
- parachutes
What is kevlar made from?
1,4-diaminobenzene and benzene-1,4-dicarboxylic acid
What is kevlar used to make?
- bulletproof vests
- boat construction
- car tyres
- lightweight sports equipment
What do reactions between dicarboxylic acids and diols make?
Polyesters
What kind of link is formed in polyesters?
An ester link.
What kind of link is formed in polyamides?
Amide link.
What is Terylene made from?
benzene-1,4-dicarboxylic acid and ethan-1,2-diol.
What is the product of hydrolysis of a condensation polymer?
The original monomers.
Why are condensation plolymers stronger and more rigid than addition polymers?
Condensation polymers have polar bonds (they have C-N and C-O bonds). So, as well as VdWs, they have dipole-dipoles and hydrogen bonds.
Give a positive and negative of polyalkenes being unreactive and chemically inert.
+ They won’t react with day-to-day chemicals (eg. coffee in a polystyrene cup)
- They are non-biodegradable.
What is a positive of condensation polymers having polar bonds?
They are open to attack from nucelophiles and therefore can be broken down by hydrolysis.
What are positives and negatives of burying waste plastic?
+ cheap
+ easy
- requires area of land
- decomposing waste can release methane
- leaks from landfill sites can contaminate water supplies
When is waste usually buried?
- difficult to separate from other waste
- not sufficient in quantity - separation not financially worthwhile
- too difficult to recycle
What is a positive and negative of burning waste plastic?
+ heat used to generate electricity
- leads to the release of toxic gases (eg. PVC releases HCl when burned)
- carbon dioxide release contributes to the greenhouse effect
How are waste gases from combustion removed?
Passed through scrubbers which can neutralise gases by reacting them with a base
What are two ways to recycle plastics?
- melt and remould
- crack into monomers
Give 4 advantages pf recycling:
+ reduces waste going to landfill
+ saves raw materials which are non-renewable
+ cost is lower than making plastics from scratch
+ produces less CO2 than burning
Give 4 disadvantages of recycling?
- technically difficult
- more expensive than burning/landfill
- often can’t make plastic you started with
- plastic can be easily contaminated during process
