Polymers

Question 1

Polymers

Answer 1

Large molecule composed of repeating structural units.

Question 2

Monomers

Answer 2

Building blocks of more complex molecules called polymers

Question 3

Two types of Polymers

Answer 3

Natural and Synthetics

Question 4

Two types of Synthetic Polymers

Answer 4

Homopolymers and Copolymers

Question 5

Homopolymers

Answer 5

Single type of repeating units

Question 6

Copolymers

Answer 6

Mixture of repeating units

Question 7

7 types of Addition Polymers

Answer 7

polyethyle, polyvinyl chloride (PVC), polstyrene (PS), polytetrafluoroethylene (PTFE), polypropylene, polyacrylanitrate (acrylics), polyvinylacetate (PVA).

Question 8

Polyethylene

Answer 8

C₂H₄ is the repeating unit

Question 9

Two types of Polyethylene

Answer 9

Low Density (LDPE) and High Density (HDPE)

Question 10

Low Density (LDPE) Polyethylene

Answer 10

• Branch like chains
• This Branching prevents the chains from packing closely together
• This results in the polymer that is softer and more flexible, but also a lower tensile strength and lower melting point
• Weaker dispersion forces
• Amorphous structure
• Flexible

Question 11

High Density (HDPE) Polyethylene

Answer 11

• Chains are more linear (like a wave ocean type thing)
• Chain are packed together more results in stronger intermolecular forces between the polymere chains
• Has greater tensile strength and higher melting points that LDPE

Question 12

LDPE Uses

Answer 12

• Plastic bags
• Packaging
• Films

Question 13

HDPE Uses

Answer 13

• Plastic Utensils
• Bottles
• Toys

Question 14

Halogenation

Answer 14

Substitute Cl for H in ethene to make Vinyl Chloride

Question 15

Polyvincly Chloride

Answer 15

• The polymer of vinyl chloride
• Chlorine atoms are randomly orientated along the chain
• Shapeless (amorphous)
• Large size due to the way Chlorine sticks out of chain
• Hard and Rigid
• C-Cl is a polar bond due to Cl being highly electronegative
• Dipole-Dipole forces add to dispersion forces between chains to make longer intermolecular forces which holds chain more strongly together
• Plasticers can be inserted in between the chain to weaken intermolecular forces between them.

Question 16

Uses of Polyvinyl Chloride

Answer 16

Construction; pipes, window frames however flexible Polyvinyl Chloride can be used for cling wrap and cable and wire.

Question 17

Styrene

Answer 17

Substitute of Benzene for H in ethene

Question 18

Polystyrene

Answer 18

• Polymer of Styrene
• Benzyl ring randomly orientated across the chain
• Mainly amorphous due to the way the ring sticks out and large size
• Symmetry means no polar bonds
• Only weak dispersion are acting to hold the chain together
• Large ring prevents polymer chain packing closely together
• Large ring prevents ability of chain to flop around so it tends to be hard and brittle
• Readily softened, moulded on heating but becomes rigid when cooled

Question 19

Polypropylene

Answer 19

• Polymer of propene
• Manufacturing this polymer requires catalysts like Zieger-Natta
• There are three variations of the structure of polypropylene and each one has different properties
• The variations differ in the placement of the -CH₃ alkyl group

Question 20

Atactic

Answer 20

• Variant of polypropylene
• Side group are randomly placed
• In the random atactic arrangement, the chains cannot lie close together so the forces of attraction are weaker
• This results in softer polymer with lower melting point
• The atactic version formed during the manufacture of the isotactic polymer is considered a waste product and is a soft rubbery polymer, which has limited use mainly as roofing materials and sealants.