9 - Biodegradable polymers

Question 1

Two categories for bio-polymers

Answer 1

• Natural bio-polymers
• Synthetic polymers

Question 2

Natural bio-polymers

Answer 2

Made from natural materials such as cellulose, starch and polysaccharides

Question 3

Synthetic bio-polymers

Question 4

Implication of the use of biodegradable polymers (3)

Answer 4

• Biodegradebale polymers can produce methane gas when they decompose in landfill - which contributes to landfill
• Can take high temperatures to decompose and may leave behind toxic residues
• They cannot be recycled as their use may not encourage people to recycle and may contribute to a throwaway culture

Question 5

When does degradation occur? (2)

Answer 5

• Degradation occurs because of the action of micro organisms, which convert the material into water, carbon dioxide biomass and possibly methane
• The ability of a polymer to biodegrade is dependant on the structure of the polymer rather than the origin of the raw material

Question 6

Light degradation (photodegradable)

Answer 6

polymer bonds are weakened and the polymer breaks down with exposure to UV light such as sunlight

Question 7

Oxygen degradation (oxy-degradable)

Answer 7

Oxygen (oxy-degradeble) - Polymer turns into fine powder with exposure to oxygen and is subsequently degraded by action of micro-organisms

Question 8

Water degradation (hydro degradable)

Answer 8

polymer quickly breaks down with exposure to water and is subsequently degraded by the action of micro-organisms

Question 9

Examples of biodegrade polymers (natural) (4)

Answer 9

• Corn starch polymer
• Potatopak
• Biopol
• PHA

Question 10

Example of biodegrade polymers (synthetic)

Answer 10

• Polylactic acid (PLA)
• Lactide
• Glucolide (lactel and Ecofilm)

Question 11

Corn starch polymer - Type and source (2)

Answer 11

• Natural bio-polymer
• Made from high-starch vegetables such as corn, potatoes and maize

Question 12

Corn starch polymer - uses (6)

Answer 12

• Packaging products
• Straws
• Vending cups
• Disposable cutlery
• Bags
• Takeaway food containers

Question 13

Potatopak - type and source (2)

Answer 13

• Natural bio-polymer
• Made from potato starch

Question 14

Potatopak - uses (7)

Answer 14

Single-use food items:

• Bowls
• Cutlery
• Food trays
• Serviettes
• Packaging beads or ‘peanuts’
• Bin bags

Question 15

Biopol - type and source (3)

Answer 15

• Natural bio-polymer
• Made from bacteria grown in cultures
• Additive to promote degradation - usually 1%.

Question 16

Biopol - uses (7)

Answer 16

Packaging products:

• Film
• Carrier bags
• Vending cups
• Nappies
• Surgical stitches
• Pill coverings

Question 17

Polylactic acid (PLA) - type and source (2)

Answer 17

• Synthetic bio-polymer
• Made from corn kernels or cane sugar which is fermented to produce lactic acid, then synthesised to produce Polylactic acid

Question 18

Polylactic acid (PLA) - uses (7)

Answer 18

• Packaging
• Single-use bottles
• Carrier bags
• Plant pots
• Disposable nappies
• Medical sutures
• 3D printing

Question 19

PHA - type and source

Answer 19

• Natural bio-polymer
• Made from bacteria grown in cultures
• Fully compostable

Question 20

PHA - uses (2)

Answer 20

• Packaging
• Medical uses such as slow-release medication patches, films, screws and bone plates

Question 21

Lactide (3)

Answer 21

• Synthetic bio-polymer
• Fully compostable, water soluble
• PLA and cellulose based

Question 22

Lactide - uses (4)

Answer 22

• Biomedical applications
• Slow release medication
• Bone repair fixings
• Detergent washing sachets

Question 23

Glycolide (lactel and Ecofilm) - type and source (3)

Answer 23

• Synthetic bio-polymer
• Fully compostable
• PLA and cellulose based

Question 24

Glycolide (lactel and Ecofilm) - uses (6)

Answer 24

• Food film
• Bags
• Packaging wrap
• Bin bags
• Agricultural ground sheet
• Flower wrap