Polymers Flashcards
All 27 cards in this deck
What is a polymer?
A substance of high average relative molecular mass made up of small repeating units.
What is a monomer?
A small molecule that joins to many others in a polymerisation reaction to form a polymer.
e.g. ethene is the monomer of poly(ethene)What is the repeating unit of a polymer?
The small section of the chain that is repeated over and over along the polymer molecule.
True or false? Every molecule in a sample of poly(ethene) has exactly the same relative molecular mass.
False. The chains are different lengths, so a polymer has a high average relative molecular mass.
What are the two types of polymerisation reaction?
Addition polymerisation and condensation polymerisation.
What is the equation for the formation of poly(ethene) from ethene?
What are the steps to draw the repeating unit of an addition polymer from its monomer?
e.g. propene,- Change the C=C to a single C–C bond.
- Draw a continuation bond out of each end carbon.
- Keep all the other atoms/groups where they are:
What are the steps to deduce the monomer from the repeating unit of an addition polymer?
e.g. repeating unit- Remove the two continuation bonds.
- Change the C–C single bond between them to a C=C double bond.
- Leave all other atoms unchanged: monomer is (chloroethene)
Give one property of poly(ethene) that makes it suitable for making containers and bags.
It is inert/unreactive and waterproof, and can be moulded into shape without breaking.
Which properties of PTFE (poly(tetrafluoroethene)) make it suitable for coating non-stick pans?
It is very unreactive, heat resistant and has a slippery, non-stick surface.
True or false? PVC is used to coat electrical wires because it conducts electricity.
False. PVC is used because it is a tough, flexible electrical insulator.
Why is a polyester described as a condensation polymer?
Because a small molecule (water) is lost each time two monomers join together.
Which two types of monomer react to form a polyester?
A monomer with two carboxylic acid groups (–COOH) and a monomer with two alcohol groups (–OH).
What small molecule is formed each time an ester link is made during polyester formation?
A molecule of water, .
What is the ester link in a polyester?
The group joining two monomer units, formed from a –COOH group and an –OH group.
True or false? A condensation polymerisation can be carried out using only one type of monomer molecule with a C=C bond.
False. A C=C monomer gives an addition polymer; condensation polymerisation uses two different monomers, each with two functional groups.
Why do polymers persist in landfill sites?
They are not biodegradable, so microorganisms cannot break them down and they degrade very slowly.
What is a problem with disposing of polymers by combustion?
Gases are produced, some of which may be toxic (e.g. hydrogen chloride from PVC).
Why must polymers be sorted before they are recycled?
Different types of polymer must be separated so that each type can be melted and reformed into a new product.
Where do the starting materials for most synthetic polymers come from?
Crude oil, which is a finite (non-renewable) resource.
Give two advantages of recycling polymers.
It conserves crude oil (the starting material) and reduces the amount of waste sent to landfill; it also uses less energy than making new polymer.
True or false? All waste polymers can be recycled easily and cheaply.
False. Some polymers cannot be recycled, and sorting, separating and washing them takes time and energy, which adds to the cost.
What are the monomers that make up DNA?
Nucleotides — DNA is made from four different nucleotides.
Proteins are polymers based on which monomers?
Amino acids.
Starch is a polymer based on which type of molecule?
Sugars.
True or false? Starch, proteins and DNA are all polymers.
True. They are natural polymers, made of repeating monomer units.
Name three natural polymers found in living things.
DNA, starch and proteins.