Micro-organisms To Aid Disposal Of Environmentally Friendly Plastics

Question 1

What are biodegradable polymers?

Answer 1

Material derived from renewable raw materials that decompose in the natural environment

Question 2

How is biodegradation of polymers achieved?

Answer 2

Micro-organisms break down molecular structure of the polymer to produce a material that is less harmful to the environment

Question 3

Give 3 advantages of biodegradable polymers

Answer 3

• Fully degradable in suitable conditions
• Reduction of time in landfill and associated harmful effects
• Doesn’t contribute to global warming

Question 4

Give 4 disadvantages of biodegradable polymers

Answer 4

• Some plastics release CO² as end product
• Damages recycled plastics when mixed
• Expensive and not widely produced
• Not as energy efficient to produce as synthetic polymers

Question 5

Give 3 applications of biodegradable polymers

Answer 5

• Packaging (Blow moulded bottles)
• Agriculture (Slow-release pesticides)
• Pharmaceutical (Coatings for pills)

Question 6

What is Biopol?

Answer 6

• First fully biodegradable polymer

- Developed commercially in 1990s

Question 7

What are the applications of Biopol?

Answer 7

• Blow moulded shampoo bottles

- ‘Green’ credit cards (20 million)

Question 8

How is Biopol produced?

Answer 8

1. Fermentation of glucose and carbohydrates collected as reserve material
2. Reserve material separated and refined from bacteria
3. Used in usual plastic manufacturing process to produce Biopol

Question 9

What is the Innocent eco-bottle?

Answer 9

• Eco-bottle made from PLA

- Derived from corn starch

Question 10

Name 3 advantages of the use of PLA in the Innocent eco-bottle

Answer 10

• Corn is renewable resource
• PLA is made using a carbon-neural process
• PLA is biodegradable

Question 11

What is the main disadvantage of the Innocent eco-bottle?

Answer 11

Only 10% of UK recycling centres have machines that can sort these bottles from normal PET and HDPE plastic bottles

Question 12

Why are plasticisers added?

Answer 12

• When plastic needs to be soft and flexible

- To assist in plastic manufacturing

Question 13

Give an example of the use of plasticisers

Answer 13

PVC outer coating of an electrical cable needs to be relatively soft and flexible to allow cable to be bent and shaped. To increase flexibility plasticisers are added

Question 14

Why are fillers added?

Answer 14

• Increase the bulk of plastics

- Reduce the overall cost of the plastics produced

Question 15

Why are fibres added?

Answer 15

When a plastic is not strong or stiff enough to carry out a task

Question 16

Give an example of a material that has had fibres added?

Answer 16

Carbon fibre (Mix of carbon fibre strands and polymer matrix)

Question 17

Name the 3 types of stabilisers used in plastics

Answer 17

• Heat stabilisers
• Light stabilisers
• Biostabilisers

Question 18

Why are heat stabilisers added?

Answer 18

Prevent plastic form decomposing during manufacturing

Question 19

Why are light stabilisers added?

Answer 19

Plastics exposed UV can become brittle and cause them to break down

Question 20

Why are biostabilisers added?

Answer 20

When plastics can be broken down due to microbiological attack, which cause the plastic to become discoloured and lose its mechanical properties

Question 21

Why are foamants added?

Answer 21

• Increase the volume of the plastic

- Increase the elasticity of the plastic

Question 22

When are plastics that contain foamants used?

Answer 22

Buoyancy aids (Air gets trapped within the cells of material, making plastic lightweight and buoyant)

Question 23

What is lamination?

Answer 23

Material has been produced by gluing together thin sheets to make up that material

Question 24

Give an example of a material that is formed through lamination

Answer 24

Plywood (Odd number of veneers, arranged so the grain on each layer is 90° to layer above and below, bonded together using epoxy-resin)

Question 25

Give 4 advantages of using lamination

Answer 25

• Economic to use (Use whole tree)
• Basic material which can be veneered
• Strong in all directions
• Can be shaped into curve (By using former)

Question 26

Give 3 disadvantages of lamination

Answer 26

• Surface finish not good
• Visible flaws (Evidence of knots)
• Delamination (If wet or damp, layers may come apart)