polymers

Question 1

What are polymers?

Answer 1

Long chain molecules made from joining short molecules called monomers together

Question 2

examples of addition polymers

Answer 2

• poly(ethene)
• poly(propene)
• Perspex
• PVC
• Teflon

Question 3

What do the properties of a polymer depend on?

Answer 3

• which monomers they are made from

- the conditions under which they are made

Question 4

Ethene- use of polymer

Answer 4

• bags

- crates/boxes

Question 5

chloroethene-use of polymer

Answer 5

• water pipes

- coating for window frames

Question 6

propene-use of polymer

Answer 6

• carpets

- crates/boxes

Question 7

tetrafluoroethene-use of polymer

Answer 7

• PTFE tape (used by plumbers)

- Non-stick coating in frying pans

Question 8

Polymers with different properties can be made using the same monomer but by changing the reaction conditions. EG: Low density and high density polyethene are both made from the monomer ethene but under different conditions

Answer 8

Low density polyethene:
-soft,flexible
-uses: bags, cling film
-monomer:ethene
- reaction conditions: 200 degrees Celsius, 2000 atmosphere, catalyst: trace of oxygen
High density polyethene 
-hard,strong
-uses: buckets, water pipes
-monomer: ethene
-reaction conditions: 60 degrees Celsius, 2 atmospheres, Catalyst: Ziegla-Natta

Question 9

Thermosoftening and thermosetting polymers

Answer 9

• The atoms within polymer chains are joined together by covalent bonds. In thermosoftening polymers, these polymer chains are not joined together
• In thermosetting polymers, the polymer chains are joined to each other by covalent bonds (often called cross-links

Question 10

structure of thermosoftening polymer

Answer 10

• contains long polymer chains

- chains are not joined to each other (but they are tangled up with each other)

Question 11

structure of thermosoftening polymer

Answer 11

• contains long polymer chains

- chains are joined to each other by covalent bonds (often called cross-links)

Question 12

What happens when thermosoftening polymers are heated?

Answer 12

They soften and melt

Question 13

Thermosetting polymer definition

Answer 13

A polymer with covalent bonds between polymer chains that does not soften or melt when heated.

Question 14

What happens when thermosetting polymers are heated?

Answer 14

They do not soften or melt

Question 15

thermosoftening polymer definition

Answer 15

A polymer with no bonds between polymer chains that softens and melts when heated

Question 16

examples of thermosoftening polymers

Answer 16

• polyethene
• PVC
• Polypropene
• Perspex
• Teflon
• Polyesters
• Nylon

Question 17

Examples of thermosetting polymers

Answer 17

• superglue
• epoxy resins
• melamine
• Bakelite

Question 18

Glass

Answer 18

-It is used for windows and containers such as bottles
-It is a very useful material that is hard, see-through and unreactive
-there are many different types of glass with slightly different properties and uses:
eg:
.soda-lime glass
.Borosilicate glass

Question 19

Soda-lime glass

Answer 19

What it is made from: sand, sodium carbonate, calcium carbonates
Uses: Windows, containers (eg: bottles)
Most of the glass we use is soda-lime glass

Question 20

Borosilicate glass

Answer 20

What it is made from: sand, boron trioxide
uses: laboratory glassware, cookware (eg: glass pans)
.melts at a higher temperature than soda-lime glass

Question 21

Clay ceramics

Answer 21

eg: bricks,pottery
- made by shaping wet clay that is then baked in a furnace or kiln
- clay ceramics are very hard, unreactive and resistant to heat.