Synthetic Polymers

Question 1

What are polymers?

Answer 1

polymers are large molecules of high relative molecular mass and are made by linking together large numbers of smaller molecules called monomers

Question 2

What is the process of linking together large numbers of smaller molecules called monomers to produce polymers called?

Answer 2

addition polymerisation

Question 3

What kind of bonds joins each monomer (repeat unit) and connect them to the adjacent units?

Answer 3

covalent bonds

Question 4

What does the polymerisation process require usually?

Answer 4

polymerisation reactions usually require high pressures and the use of a catalyst

Question 5

What are some examples of everyday materials that are polymers?

Answer 5

resins, plastics, polystyrene cups, nylon

Question 6

What are materials such as: resins, plastics, polystyrene cups, nylon usually called?

Answer 6

synthetic polymers

Question 7

What are the polymers that nature can produce called?

Answer 7

natural or biological polymers

Question 8

What are the 3 stages of polymerisation?

Answer 8

monomer —> polymerisation —> polymer

Question 9

What do monomers have to contain to be able to become addition polymers?

Answer 9

C=C bonds

Question 10

What happens to the structure of a monomers when becoming an addition polymer?

Answer 10

one of the bonds in each C=C bond breaks and forms a bond with the adjacent monomer with the polymer being formed containing single bonds only

Question 11

What are many addition polymers made of?

Answer 11

many polymers can be made by the addition of alkene monomers

Question 12

What are other addition polymers made of if it is not the addition of alkene monomers?

Answer 12

others are made from alkene monomers with different atoms attached to the monomer such as chlorine or a hydroxyl group

Question 13

How are polymers named?

Answer 13

the name of the polymer is deduced by putting the name of the monomer in brackets and adding poly- as the prefix

Question 14

What does the name of all polymers begin with?

Answer 14

poly-

Question 15

What is poly (ethene) formed by?

Answer 15

polyethene is formed by the addition polymerisation of ethene monomers

Question 16

If propene is the alkene monomer used, what is the name of the polymer?

Answer 16

poly (propene)

Question 17

How would you draw a repeating unit for addition polymers?

Answer 17

repeat units are used when displaying the formula

to draw a repeat unit, change the double bond in the monomer to a single bond in the repeat unit

add a bond to each end of the repeat unit

the bonds on either side of the polymer must extend outside the brackets (these are called extension or continuation bonds)

a small subscript n is written on the bottom right hand side to indicate a large number of repeat units

add on the rest of the groups in the same order that they surrounded the double bond in the monomer

Question 18

How would you deduce the monomer from the polymer?

Answer 18

identify the repeating unit in the polymer

change the single bond in the repeat unit to a double bond in the monomer

remove the bond from each end of the repeat unit and the subscript n (which can be placed in front of the monomer)

Question 19

How are addition polymers formed?

Answer 19

addition polymers are formed by the joining up of many small molecules with strong C-C bonds

Question 20

What are some key features of addition polymers and why are they features?

Answer 20

addition polymers are unreactive and chemically inert so don’t easily biodegrade because of the strong C-C bonds

Question 21

How do addition polymers affect landfills?

Answer 21

waste polymers are disposed of in landfill sites but this takes up valuable land, as addition polymers are non-biodegradable so micro-organisms such as decomposers cannot break them down

this causes sites to quickly fill up

Question 22

How does the burning of addition polymers contribute to the release of toxic gases as well as affecting humans?

Answer 22

polymers release a lot of heat energy when they burn and produces carbon dioxide which is a greenhouse gas that contributes to climate change

polymers that contain chlorine such as PVC release toxic hydrogen chloride gas when burned

if incinerated (burned) by incomplete combustion, carbon monoxide will be produced which is a toxic gas that reduces the capacity of the blood to carry oxygen

Question 23

What is the meaning of biodegradable?

Answer 23

the breakdown of a substance by microorganisms

Question 24

When are condensation polymers formed and how?

Answer 24

condensation polymers are formed when two different larger monomers are linked together with the removal of a smaller molecule, usually water or hydrogen chloride

Question 25

What is the key difference between condensation polymers and addition polymers?

Answer 25

addition polymerisation forms the polymer molecule only condensation polymerisation forms the polymer molecule and one water molecule per linkage

Question 26

What are polyesters formed by?

Answer 26

a dicarboxylic acid (a carboxylic acid with two -COOH- groups) and a diol (an alcohol with two -OH- groups)

Question 27

Which of the larger monomers gives the -OH molecule to create the by-product of water?

Answer 27

the dicarboxylic acid

Question 28

For every ester linkage formed in condensation polymerisation, what is released?

Answer 28

for every ester linkage formed in condensation polymerisation, one molecule of water is formed from the combination of a -H and an -OH group

Question 29

What happens during condensation polymerisation?

Answer 29

each -COOH group reacts with another -OH group on another monomer an ester linkage is formed with the subsequent loss of one water molecule per link

Question 30

Which of the larger monomers gives the -H molecule to create the by-product of water?

Answer 30

the diol

Question 31

How can the structure of polyester be drawn?

Answer 31

they can be represented by drawing out the polymer using boxes to represent the carbon chains this can be done for all polyesters

Question 32

When trying to deduce the two larger monomers from the polyester, how should you think of it?

Answer 32

it helps to think of this as the reversal of the formation of a polyester when a polyester is formed, small molecules of water are removed the OH comes from the acid / -COOH groups of the dicarboxylic acid the H comes from the alcohol / -OH groups of the diol

Question 33

What is the process of adding water to the polyester to allows it to break back down into its monomers?

Answer 33

hydrolysis

Question 34

What is the key point you should remember about polyesters?

Answer 34

when the polyester was made, the dicarboxylic acid lost OH groups and the diol lost H atoms

Question 35

What are biopolyesters?

Answer 35

biopolyesters are a specific type of polymers that are synthesised from sugars and plant oils using microorganisms

Question 36

What are biopolyesters able to do that regular polyesters cannot?

Answer 36

they are able to biodegrade naturally in the environment after their intended purpose

Question 37

Why are biopolyesters biodegradable?

Answer 37

the polymers are synthetically made, consisting of ester, amide and ether functional groups which gives them the characteristic of being biodegradable