Properties of plastics

Question 1

LDPE conditions properties

Answer 1

higher temperature (200 degrees) and pressure, low density, low tensile strength, flexible and ductile

Question 2

HDPE conditions properties

Answer 2

lower temperature (50 degrees) and pressure and catalyst, high density, high tensile strength, rigid

Question 3

Low and high density polyethene definition

Answer 3

made from ethene monomers by changing polymerisation conditions you can change the density and therefore their properties

Question 4

Thermosoftening plastic structure

Answer 4

tangled polymer chains held together with weak intermolecular forces, forces break at low temperature, when melted its flexible so can be reshaped, when it cools the chains move closer together to from new intermolecular forces

Question 5

Thermosetting plastic structure

Answer 5

polymer chains held together with cross link bonds, bonds don’t break, polymer is rigid, strong and hard

Question 6

LDPE structure

Answer 6

branched polymer chains = less polymer chains in a given volume, polymer are far apart so less intermolecular forces

Question 7

HDPE structure

Answer 7

polymer chains are not branched = more polymer chains in a given volume, polymers are close together so more in termolecular forces