24 - Polymers

Question 1

What is a polymer?

Answer 1

A substance of high average relative molecular mass made up of small repeating units

Question 2

What is polymerisation?

Answer 2

The process in which monomers join together

Question 3

Why don’t Polymers have a specific relative molecular mass?

Answer 3

The polymer molecules can be different lengths

Question 4

What is Addition Polymerisation?

Answer 4

Many small molecules (monomers) join together to create very large molecules (polymers)

Question 5

What is poly(ethene)?

Answer 5

A polymer formed when a large number of ethene monomers join together

Question 6

Describe how ethene molecules form poly(ethene)

Answer 6

Ethene molecules have a double covalent bond between carbon atoms

One of the bonds in the double bond breaks open & another ethene molecule adds on

Process repeats, forming a long chain

Addition polymer is poly(ethene)

Question 7

What process is used to combine ethene molecules to make poly(ethene)?

Answer 7

Addition polymerisation

Question 8

What type of bond does Ethene molecules have between the carbon atoms?

Answer 8

Double covalent bond

Question 9

What is the repeating unit?

Answer 9

Shows how the monomer has changed & how it repeats throughout the polymer chain

Question 10

What is a synthetic polymer?

Answer 10

A polymer that is manufactured in a laboratory or factory

Question 11

What type of polymer is poly(ethene)?

Answer 11

A synthetic polymer

Question 12

Give some examples of naturally occurring polymers

And give the monomers of each polymer named

Answer 12

• DNA - nucleotides
• Starch - glucose
• Protein - amino acids

Question 13

What is the general equation for ANY addition polymerisation?

Answer 13

Question 14

What are the properties of Poly(ethene)?

Answer 14

• Flexible
• Cheap
• Electrical insulator

Question 15

What are the uses of Poly(ethene)?

Answer 15

• Plastic bags
• Coating on electrical wires

Question 16

What are the properties of Poly(propene)?

Answer 16

• Flexible
• Strong

Question 17

What are the uses of Poly(propene)?

Answer 17

• Buckets
• Crates

Question 18

What are the properties of Poly(chloroethene)?

Answer 18

• Tough
• Cheap
• Long lasting

Question 19

What are the uses of Poly(chloroethene)?

Answer 19

Window frames

Question 20

What is Poly(chloroethene) also known as?

Answer 20

PVC

Question 21

What are the characteristics of PFTE?

Answer 21

• Tough
• Non-stick

Question 22

What are the uses of PFTE?

Answer 22

Non stick coating on pans

Question 23

What is condensation polymerisation?

Answer 23

When monomers join together & eliminate a small molecule (e.g. water)

Question 24

What is the functional group of Esters?

Answer 24

-COO-

Question 25

How are **Esters** formed?

Answer 25

Carboxylic acid reacts with an alcohol in the presence of a catalyst

Question 26

What are the **requirements** to form a **long chain** of monomers?

Answer 26

Each monomer must have 2 functional groups, one at each end of the molecule

Question 27

What is an **Ester link**?

Answer 27

Link is present in all polyester molecules ---> Consists of -COO-

Question 28

What are some **problems** associated with **polymers**?

Answer 28

* Crude oil is finite & non-renewable * Polymers are non-biodegradable - they cannot rot in landfill sites * Greenhouse gases are produced during disposal by combustion * Polymers need to be sorted correctly so that they can be melted and reformed into a new product

Question 29

Why is it a **problem** that ** crude oil is **finite & non-renewable** for **polymers**?

Answer 29

Most of the monomers needed to make synthetic polymers are obtained from crude oil ---> Chemists will need to find new sources of monomers in the future

Question 30

What does **biodegradable** mean?

Answer 30

A substance that can be broken down by microorganisms

Question 31

How can we **reduce the amount of waste** that goes into incinerators or landfill sites?

Answer 31

* By reducing amounts of materials we use & reusing materials * By recycling

Question 32

What are the **benefits** to **reducing the amount of waste** that goes into incinerators or landfill sites?

Answer 32

* Helps conserve supplies of crude oil * Less greenhouse gases are released into the atmosphere

Question 33

How can we **make the sorting** of **polymers** easier?

Answer 33

Codes & symbols are used on plastic items to show what they are made of

Question 34

Why is it **difficult** to **recycle polymers**?

Answer 34

Many steps are needed to obtain a new item