C11: Polymers

Question 1

What are polymers?

Answer 1

Polymers are very long molecules made up of lots of smaller molecules joined together in a repeating pattern. The smaller molecules are called monomers. The process of turning many monomers into a polymer is called polymerisation.

Question 2

What are the two types of polymerisation?

Answer 2

Addition polymerisation
Condensation polymerisation

Question 3

What are the products of addition polymerisation?

Answer 3

Just the polymer

Question 4

What are the products of condensation polymerisation?

Answer 4

Polymer and water

Question 5

What are the monomers in addition polymerisation?

Answer 5

Molecules with C=C bonds, alkenes

Question 6

What are the monomers in condensation polymerisation?

Answer 6

Diols, dicarboxylic acids, or diamines

Question 7

What is addition polymerisation?

Answer 7

Addition polymerisation starts with molecules with a C= C bond (e.g., alkenes) as the monomer. The carbon-carbon pi double bond breaks in each molecule, and the carbon atoms then link together.

Question 8

What is the displayed representation of polymers?

Answer 8

The n refers to a large number of molecules. The rounded brackets and the bonds sticking out of them represent where the next molecule in the chain goes.
The inside of the brackets is known as the repeating unit - the section that repeats over and over again many thousands of times in the polymer.

Question 9

How are addition polymers named?

Answer 9

Addition polymers are named after the monomer used to create them.
• An addition polymer made of ethene is called poly(ethene).
• An addition polymer made of propene is called poly(propene).

Question 10

What are two examples of products of addition polymerisation and uses?

Answer 10

• Vinyl chloride polymerises to form poly (vinyl chloride)- PVC- drain pipes and window frames
• Tetrafluoroethylene polymerises to form poly fluorine- PTFE or Teflen- nonstick coating for pans

Question 11

Why is disposal of plastic waste problematic?

Answer 11

• Landfills quickly fill up and plastic doesn’t decompose for hundreds of years as it isn’t biodegradable and resistant to chemical reactions
• Burning plastic releases CO2 contributing to global warming and releasing other toxic gases as they burn

Question 12

What two monomers are used in condensation polymerisation?

Answer 12

Diols: 2 -OH groups at either end
Dicarboxylic acid: -COOH group at either end

Question 13

What is the process of condensation polymerisation?

Answer 13

-When the diol and dicarboxylic acid react together, the -OH group from carboxylic acid and a hydrogen atom from the -OH group on the alcohol join together to form water
- Another diol and dicarboxylic acid can react with either side of the molecule that has been formed, forming a long chain polymer
- Each time a molecule is added, a water molecule is produced

Question 14

What impacts the melting/ boiling point of polymers?

Answer 14

• Bonds within the polymers are strong covalent bonds and so require high temperatures to break
• However, only weak intermolecular forces between molecules are broken determining the melting/boiling point of the polymer
• Therefore long polymers with high surface areas and many intermolecular forces have a relatively high melting/boiling point

Question 15

What do the properties of polymers depend on?

Answer 15

The properties of polymers depend on both the monomer and conditions used to make the polymers e.g./high density, polythene – different conditions, same monomer
Can change reaction temperature, reaction pressure or the catalyst used

Question 16

What are thermosoftening polymers?

Answer 16

Thermo softening polymers melt when heated
We can then reshape them whilst they’re soft and they can return solid when they’re cooled.

Question 17

What is the process of heating and reshaping thermosoftening polymers?

Answer 17

When we heat the polymer into molecular forces break. Now polymer strands can separate from each other and the polymer melts.
If we call the melted polymer, we reform the intermolecular forces so the polymer returns to solid

Question 18

What are thermosetting polymers?

Answer 18

Setting polymers do not melt when heated due to strong cross links which are not broken by heat or high temperatures

Question 19

How are diols named?

Answer 19

Alkane-(no. position on C of -OH functional group)- diol

Question 20

What is DNA?

Answer 20

All genetic information is stored in DNA. Genetic information contains the instructions for the functioning and development of living organisms.

Question 21

How is DNA structured?

Answer 21

DNA is made of two long polymers that wind around each other in a double helix. The polymers are made of four different monomers called nucleotides.
Each nucleotide has a phosphate group, a sugar and base

Question 22

Give examples of natural polymers

Answer 22

Polypeptides
Starch
Cellulose
DNA

Question 23

What are amino acids?

Answer 23

The building blocks for polypeptides and proteins, which have an amine and carboxylic acid group

Question 24

What is a polypeptide?

Answer 24

A polymer made when many molecules of glycine (amino acid) react together

Question 25

What is the functional group of amines?

Answer 25

The amine functional group has a nitrogen bonded to a carbon and two hydrogens. NH2

Question 26

What is the simplest amino acid and formula?

Answer 26

Glycine C2H5NO2 Carboxylic acid and amine functional group of each side, with CH2 in centre

Question 27

How are proteins formed?

Answer 27

When many polypeptides come together

Question 28

What is a peptide bond?

Answer 28

O || C—N | H

Question 29

What is the monomer of starch and cellulose?

Answer 29

Glucose

Question 30

What is the monomer of DNA?

Answer 30

nucleotides

Question 31

What is the monomer of proteins?

Answer 31

Amino acids