9-Biodegradeable polymers Flashcards
What is a negative of synthetic polymers?
- They can take hundreds of years to break down (Degrade)
- This is a major cause of pollution and can kill marine and bird life
What is a Bio-polymer?
Polymers made from natural renewable resources
what are the two categories of Biopolymers?
- Natural
- Synthetic
Natural Bio-polymers
- Polymers made from natural materials such as starch
Synthetic bio-polymers
- polymers made from renewable resources but chemically synthesised to degrade faster
what is a biodegradable polymer?
Made from finite resources but contains additives which cause it to degrade faster
2 positives of bio-polymers/biodegradable polymers
- Reduces the dependence on fossil fuels and fractional distillation which massively reduces pollution levels and energy usage
- Can be processed in the same way as other regular polymers therefore machinery would not need to be changed
1 negative of bio-polymers
- Biopolymers will need lots of land space and water to grow the crops for the polymers
1 negative of biodegradable polymers
- Can take high temperatures to decompose which can use a lot of energy
- This combustion can emit toxic gases
2 Biopolymers (synthetic)
- Polylactic acid
- Lactide
2 bio-polymers (natural)
- Corn starch polymer
- Potatopak
Potatopak
- Made from potato starch
- For single use food items such as bowls, cutlery, trays, or used as packaging peanuts
Lactide
- Fully compostable, PLA and cellulose based
- Food film, bin bags
Corn starch polymer
- Made from high starch vegetables such as corn or potatoes
- Used in packaging, disposable cutlery, straws
Polylactic acid (PLA)
- Made from corn kernels or cane sugar, fermented to create lactic acid, and then synthesized to make polylactic acid
- used in nappies, 3D printing, medical stitches, plant pots, and more
What are the 3 environmental factors that can affect degradation?
- Light (Photodegradation)
- Oxygen (Oxy-degradation)
- Water (Hydrodegradation)
How does degradation occur and what is it dependant on?
Micro organisms convert material in the polymer into other substances such as water or carbon dioxide
- The ability to degrade is dependant on the structure of the polymer as opposed the the origin of the raw material
How short can a Bio-polymer be designed to degrade?
- a few months
Photodegradation (Light)
- Polymer bonds are weakened by exposure to UV light
Oxy-degradation (Oxygen)
Oxygen converts the polymer into a fine powder which is then degraded by microorganisms
Hydro-degradation (water)
- Polymer breaks down due to water exposure and is then degraded by microorganisms
