CHAPTERS 9.1-9.5

Question 1

what are polymers?

Answer 1

plastics, they are used in the construction of many different objects because they are cheap, versatile and easy to manufacture

Question 2

what is the structure of polymers?

Answer 2

covalent molecular substances composed of many small molecules all joined together (long chains made up of many small units called monomers)

Question 3

what is addition polymerisation?

Answer 3

the reaction of an alkene with another molecule . all of the atoms of both molecules are present in the final molecule

Question 3

what is addition polymerisation?

Answer 3

the reaction of an alkene with another molecule . all of the atoms of both molecules are present in the final molecule

Question 3

what is addition polymerisation?

Answer 3

the reaction of an alkene with another molecule . all of the atoms of both molecules are present in the final molecule

Question 4

what is addition polymerisation?

Answer 4

the reaction of an alkene with another molecule. all of the atoms of both molecules are present in the final molecule

Question 5

what is the difference between low and high density polyethene?

Answer 5

low density polyethene
- relatively soft
- low melting point
- non-crystalline

high density polyethene
- hard
- higher melting point than LDPE
- crystalline sections

Question 6

what two groups can polymers be classified into?

Answer 6

• thermoplastic polymers
• thermosetting (or thermoset) polymers

Question 7

what are some properties of thermoplastic polymers?

Answer 7

• softened when heated
• between the long polymer chains are hydrogen bonds and dipole-dipole attractions, or weak dispersion forces
• most addition polymers are thermoplastic

Question 8

what are some properties of thermosetting polymers?

Answer 8

• covalent bonds between polymer molecules called cross-links
• decompose or burn when heated
• strong covalent bonds between chains
• cannot be remoulded into new shapes

Question 9

what are some properties of elastomers?

Answer 9

• formed when only cross-links are present (rare)
• cross-links stop elastomers from completely melting when heated
• noon-recyclable

Question 10

what is polystyrene?

Answer 10

side groups that are covalently bonded to every second carbon atom in the polymer chain (causes it to be a hard and brittle plastic)

Question 11

what are microplastics?

Answer 11

plastics items that have broken up into smaller pieces