PL - Polymers

Question 1

What are the two ways of making polymers?

Answer 1

Addition polymerisation and condensation polymerisation.

Question 2

What are addition polymers formed from?

Answer 2

Alkenes.

Question 3

How do alkenes form addition polymers?

Answer 3

The double bonds in alkenes can open up and join together to make long chains called addition polymers.

Question 4

What are the monomers for addition polymers?

Answer 4

Alkenes.

Question 5

What do condensation polymers include?

Answer 5

Polyesters and polyamides.

Question 6

What does condensation polymerisation usually involve?

Answer 6

Two different types of monomer each of which has at least two functional groups.

Question 7

How are condensation polymers formed?

Answer 7

Condensation polymerisation usually involves two different type of monomer, each of which has at least two functional groups. Each functional group reacts with a group on another monomer to form a link, creating polymer chains.

Question 8

In condensation polymerisation, what is lost every time a link is formed?

Answer 8

A small molecule (usually water).

Question 9

What is an example of a natural condensation polymer?

Answer 9

Proteins.

Question 10

What are the two types of condensation polymer that you need to know about?

Answer 10

Polyesters and polyamides.

Question 11

What are polyamides made from?

Answer 11

Dicarboxylic acid and diamine monomers.

Question 12

What reacts between a dicarboxylic acid and a diamine to form a polyamide/amide links?

Answer 12

Carboxyl groups react with amino groups to form amide links.

Question 13

What causes an amide link to form?

Answer 13

Carboxyl groups react with amino groups to form amide links.

Question 14

What links are formed in the condensation polymerisation which makes a polyamide?

Answer 14

Amide links.

Question 15

What size are the chains that polyamides form?

long or short?

Answer 15

They form long chains as dicarboxylic acids and diamines have functional groups at each end of the molecule, so long chains form.

Question 16

What can the amide links in polyamides be broken down by?

Answer 16

Hydrolysis.

Question 17

What does the hydrolysis of polyamides reform?

Answer 17

The dicarboxylic acid and diamine monomers.

Question 18

What are polyesters made from?

Answer 18

Dicarboxylic acid and diol monomers.

Question 19

What reacts between a dicarboxylic acid and a diol to form a polyester/ester links?

Answer 19

Carboxyl groups (-COOH) react with hydroxyl (-OH) to form ester links (-COO-).

Question 20

What polymer is formed from a dicarboxylic acid and a diamine?

Answer 20

A polyamide.

Question 21

What polymer is formed from a dicarboxylic acid and a diol?

Answer 21

A polyester.

Question 22

What links are formed in the condensation polymerisation which makes a polyester?

Answer 22

Ester links.

Question 23

What causes an ester link to form?

Answer 23

Carboxyl groups (-COOH) react with hydroxyl (-OH) to form ester links (-COO-).

Question 24

What can the ester links in polyesters be broken down by?

Answer 24

Hydrolysis.

Question 25

What does the hydrolysis of polyesters reform?

Answer 25

The dicarboxylic acid and diol monomers.

Question 26

How do you show something is a polymer repeating unit?

Answer 26

Draw brackets around where it repeats/the repeating unit and put an ‘n’ after it.

Question 27

What do you join together to find a condensation polymer?

Answer 27

The monomer functional groups.

Question 28

How do you work out the (formula of the) condensation polymer that would form from 2 monomers?

Answer 28

• Draw out the two monomer molecules next to each other.
• Remove an OH from the dicarboxylic acid, and an H from the diamine/diol to give a water molecule.
• Join the C and the N/O together to make an amide/ester link.
• Take another H and OH off the ends of your molecule.
• Draw brackets around the molecule, add an ‘n’ outside the brackets and there’s the formula of your polymer.

Question 29

What does the ‘n’ after the brackets show?

Answer 29

That you’ve got lots of the monomers, and the polymer contains lots of the section shown in the brackets.

Question 30

What is the ‘repeat unit’ of a polymer?

Answer 30

The same as the structural formula, but you don’t need the brackets or the ‘n’.

Question 31

What do you break to find the monomers of a condensation reaction?

Answer 31

The amide or ester link.

Question 32

How can you find the formulas of the monomers used to make a condensation polymer?

Answer 32

By looking at its formula.
1) First find the amide (HN-CO) or ester (CO-O) link. Break it down the middle.
2) The add a H or an OH to both ends of both molecules to find the monomers.
(Always add Hs to O or N atoms, and OH groups of C atoms.)

Question 33

How do you know where to add the Hs and Oh groups when breaking up a condensation polymer into its monomers?

Answer 33

Always add Hs to O or N atoms, and OH groups of C atoms.

Question 34

What can molecules that contain both an amine and an alcohol group do?

Answer 34

React with dicarboxylic acids in a condensation polymerisation reaction so that the polymers contain both amide and ester links.

Question 35

How are polymers that contain both amide and ester links shown?

Answer 35

One of the links is in the ‘middle’ of the molecule and the other link is split across the ends of the polymer formula.

Question 36

Why can it be hard to see that a polymer contains both ester and amide links?

Answer 36

Because ne of the links is in the ‘middle’ of the molecule and the other link is split across the ends of the polymer formula.

Question 37

What can a single molecules that contain both a carboxylic acid group and either an alcohol or an amine group do?

Answer 37

It can polymerise itself to form a condensation polymer with only one monomer.

Question 38

What are the differences in terms of the type of monomer in addition polymers and condensation polymers?

Answer 38

Addition polymers - alkenes.

Condensation polymers - each monomer must have at least two functional groups able to react. E.g. diols and dicarboxylic acids (to form polyesters), or diamines and dicarboxylic acids (to form polyamides).

Question 39

What are the differences in terms of the polymerisation reaction in addition polymers and condensation polymers?

Answer 39

Addition polymers - addition reaction, where the C=C bonds in the alkene monomers open up and join together to form long chains.

Condensation polymers - condensation reactions, where the functional groups on alternate monomers react together to form an amide or ester link, resulting in water being released.

Question 40

What are the differences in terms of polymer reactivity in addition polymers and condensation polymers?

Answer 40

Addition polymers - the main polymer chain is unreactive.

Condensation polymers - the links between monomers are amide or ester links, which can be hydrolysed under acidic or basic conditions, to break down the polymer and reform the original monomers.

Question 41

What are the 3 differences between addition polymers and condensation polymers?

Answer 41

Type of monomer:

1) Addition polymers - alkenes.
2) Condensation polymers - each monomer must have at least two functional groups able to react. E.g. diols and dicarboxylic acids (to form polyesters), or diamines and dicarboxylic acids (to form polyamides).

Polymerisation reaction:

1) Addition polymers - addition reaction, where the C=C bonds in the alkene monomers open up and join together to form long chains.
2) Condensation polymers - condensation reactions, where the functional groups on alternate monomers react together to form an amide or ester link, resulting in water being released.

Polymer reactivity:

1) Addition polymers - the main polymer chain is unreactive.
2) Condensation polymers - the links between monomers are amide or ester links, which can be hydrolysed under acidic or basic conditions, to break down the polymer and reform the original monomers.

Question 42

Give an example of a polyamide:

Answer 42

Nylons.