Addition polymers

Question 1

Polymers are large molecules made from many…

Answer 1

Monomers

Question 2

What are addition polymers made from?

Answer 2

Monomers based on ethene.

Question 3

Draw the general formula for an addition polymer monomer.

Answer 3

w

Question 4

How do ethene monomers form an addition polymer?

Answer 4

Their carbon to carbon double bonds break and the monomers form together to form a backbone of carbon atoms.

Question 5

How would the formation of an addition polymer be shown as a formula?

Answer 5

j

Question 6

What does many ethene molecules polymerise to form?

Answer 6

poly(ethene)

Question 7

What does many phenylethene polymerise to form?

Answer 7

Poly(phenylethene)

Question 8

What is another name for phenylethene?

Answer 8

Styrene

Question 9

What is another name for poly(phenylethene)

Answer 9

Polystyrene

Question 10

What is poly(ethene) typically used for?

Answer 10

Carrier bags and washing up bowls

Question 11

What is the common name for poly(ethene)?

Answer 11

Polythene

Question 12

What is the common name for poly(propene)?

Answer 12

Polypropylene

Question 13

What is poly(propene) typically used for?

Answer 13

Yoghart containers and car bumpers

Question 14

What is the common name for poly(chloroethene)?

Answer 14

PVC (polyvinylchloride)

Question 15

What is poly(chloroethene) typically used for?

Answer 15

Aprons, vinyl records and drainpipes

Question 16

What is the common name for poly(propenenitrile)?

Answer 16

Acrylic

Question 17

What is poly(propenenitrile) typically used for?

Answer 17

Clothing fabrics

Question 18

What is the typical use for poly(phenylethene)?

Answer 18

Packaging and electrical insulation

Question 19

What are plasticisers?

Answer 19

Small molecules that can modify polymers

Question 20

How do plasticisers modify polymers?

Answer 20

They get between the polymer chains and force them apart. This allows them to slide across each other (making them more flexible)

Question 21

Why are polyalkenes not biodegradable?

Answer 21

They have strong, non-polar C-C and C-H bonds and so they are very unreactive molecules and are not attacked by biological agents, such as enzymes.

Question 22

How do you create low density poly(ethene)

Answer 22

Polymerising ethene via free-radical reactions at high pressure and high temperature.

Question 23

Low desity poly(ethene) has rather a lot of chain branching due to the random nature of free radical reactions. What affect does this have on the properties of low density(polyehtene)?

Answer 23

The branched chains do not pack together well and so it is quite flexible, stretches well and has low density.

Question 24

What are the typical used for low density poly(ethene)?

Answer 24

Plastic bags, sheeting and insulation for electrical cables

Question 25

How is high density poly(ethene) made?

Answer 25

At high temperatures and pressure little greater than room conditions and with the aid of a Ziegler-Natta catalyst.

Question 26

High density poly(ethene) has little chain branching. How does this affect the properties of high density poly(ethene)?

Answer 26

The chains are able to pack together well and so the density if the plastic is greater and it's meting point higher.

Question 27

What are the typical used of high density poly(ethene)?

Answer 27

Milk crates, buckets and bottles

Question 28

How could we reduce the amount of plastics being sent to landfills?

Answer 28

Reuse or recycle the plastics

Question 29

What are the two different types of recycling?

Answer 29

Mechanical and feedstock

Question 30

What is the process of mechanical recycling?

Answer 30

The different types of plastics are separated and wash them. They are then ground up into small pellets and melted and remoulded.

Question 31

What is the process of feedstock recycling?

Answer 31

The plastics are heated to a temperature that will break the polymer bonds ad produce monomers. The monomers are then used to make new plastics.

Question 32

What is the problem with recycling plastics?

Answer 32

Some plastics can only be heated up a certain amount of times because after each time it is heated it changes shape (some of the chains break and become shorter). This degrades the plastics properties.