Biodegradable Polymers Flashcards
CH9
What are the two main categories of Biopolymers?
- Natural Bio-polymers
- Synthetic Bio-polymers
What are Natural Bio-polymers made of?
Made from natural materials such as cellulose, starch and polysaccharides
What are Synthetic Bio-polymers made of?
Made from renewable resources but chemically engineered (synthesised) to break down more quickly
What are the implications of using Biodegradable polymers?
- They can produce methane gas when they decompose in landfill
- They can take high temperatures to decompose and may leave behind toxic residue
What is meant by biodegradable polymers?
they are made from finite resources such as crude oil and contain additives that cause them to degrade more quickly than traditional polymers
What are the implications of using Bio-polymers polymers?
- Natural bio-polymers need land to grow the crops to make them, including GM crops
What are the implications of using Bio-polymers polymers AND Biodegradable polymers?
- They cannot be recycled
- They have different meanings, which may be confusing to people thus they cannot make informed environmental choices
- They can be processed in the same way as thermoplastics (ex injection moulded, blow moulded, calendered and vacuum formed)
Name 4 natural bio-polymers
Corn starch polymer
Potatopack
Biopol (trader name foe PHB)
PHA
Name 3 synthetic bio-polymers
Polylactic Acid (PLA)
Lactide
Glycolide (Lactel and Ecofilm)
Where does Corn starch polymer come from and what is it used for?
It is made from high-starch vegetables such as corn, potatoes and maize
- packaging products, straws, vending cups, disposable cutlery, bags, takeaway food containers
Where does Potatopack come from and what is it used for?
Made from potato starch (the production process of Potatopak products is pro-environment. It involves recycling the starch water from potato processing, reducing factory waste, and preventing disposal down drains or use as pasture irrigation)
- single use food items such as bowls, cutlery, food trays, napkins, bin bags
What is the difference in recycling between potato pack and PLA?
Potatopak decomposes more quickly and can be composted at home, while PLA requires specific conditions and facilities for recycling and decomposes very slowly
Where does Biopol (bio batch additive) come from and what is it used for?
Made from bacteria grown in cultures
Additive to promote degradation
Usually 1% added to thermoplastic
- packaging products such as film, carrier bags, vending cups, nappies, surgical stiches, pill coverings
Where does Polylactic Acid (PLA) come from and what is it used for?
Made from corn kernels or cane sugar, fermented to produce lactic acid, then synthesised to produce polylactic aid.
- Packaging, single use bottles, carrier bags, plant pots, disposable nappies, medical sutures, 3D printing
Where does PHA come from and what is it used for?
Made from bacteria grown in cultures. Fully compostable
- Packaging, medical uses such as slow release medication patches, films, screws and bone plates
Where does Lactide come from and what is it used for?
Fully compostable, water soluble.
PLA and cellulose based
- Biomedical applications, slow release medication, bone repair fixing, detergent washing sachet
Where does Glycolide (Lactel and Ecofilm) come from and what is it used for?
Fully compostable. PLA and Cellulose based
- Food films, packaging wrap, bin bags, flower wrap, agricultural ground sheet
How long does it take for biopolymers to degrade?
From a few months to a couple of years
What are Photodegradable Bio-Polymers?
They are biopolymers that degrade in the presence of light. Polymer bonds are weakened and the polymer breaks down with exposure to UV light, such as sunlight
What are Oxy-degradable Bio-Polymers?
They are biopolymers that degrade in the presence of Oxygen. Polymers turn into fine powder with exposure to oxygen and are then degraded by the action of microorganisms
What are Hydro-degradable Bio-Polymers?
They are biopolymers that break down in the presence of Water and are then degraded by the action of microorganisms
How does degradation occur in biopolymers?
It occurs because of the action of micro-organisms, which convert the material into water, CO2, biomass and possibly methane
What does the ability of a polymer to biodegrade depend on?
The structure of the polymer, not the origin of the raw material
