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Potatoes to Plastic. Making bio-plastic from starch. What is Plastic?. Plastic is a common term for a wide variety of synthetic or semi-synthetic materials suitable for use in manufacture. Plastics usually made up of polymers and often created from petroleum products.
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Potatoes to Plastic Making bio-plastic from starch
What is Plastic? • Plastic is a common term for a wide variety of synthetic or semi-synthetic materials suitable for use in manufacture. • Plastics usually made up of polymers and often created from petroleum products.
What’s so great about plastic? • Malleability • Versatility • Low cost
What’s not so great about plastic? • About 8% of the worlds oil is used in plastic manufacture, 4% for raw materials, and 4% for energy • Plastic products account for 35% of all litter
What is bio-plastic? • Bioplastic is a from of plastic derived from renewable biomass sources, such as vegetable oil or corn starch.
Biodegradable? • Biodegradation is a process where organic materials are broken down by natural processes and micro-organisms. • All bio-plastics and conventional plastics are technically biodegradable. But, some break down slowly that they are considered practically non-biodegradable. • Quite a lot of bioplastics will only biodegrade under very strict circumstances, most will not biodegrade in landfill.
The Pro’s: Bioplastic • Bioplastics are made from plant based sources, not from fossil fuels so introduce no new carbon from materials source.
The cons: Bioplastic • Most bioplastic manufacturers use oil products to fuel the production process. This uses about 80% of the fossil fuel used in conventional plastic production. • Problems of large scale mono-cropping • Destruction of rainforest
But… • Bioplastic produced on a smaller scale, planted with biodiversity in mind and produced using renewable energy really is a sustainable option. • One way of doing this is to make plastic from locally grown potatoes.
Health and Safety • Grating • Acid • Sodium Hydroxide • Heat • Gloves • Goggles
Extracting starch • Grate about 100g of clean potato • Add 100cm3 distilled water to the potato and grind in a pestle and mortar • Strain the liquid off, and repeat adding distilled water, grinding and straining twice more. • Leave to settle for 5 mins • Strain the water off, leaving the starch behind.
Turning starch to plastic… • Potato starch is made from two carbohydrate polymers, amylose and amylopectin. • Amylopectin needs to be broken down in order for the starch to be plasticised.
Turning potato to plastic… • Put 25cm3 water (distilled) into a beaker and add 2.5g starch and 3mlhydrochloric acid and 2cm3 pure glycerol. • Bring to the boil for 15 mins, ensuring it doesn’t boil dry • Using indicator paper and sodium hydroxide to neutralise the solution (probably about 3ml).
Turning starch to plastic… • Add a few drops of colouring to the mixture and mix in. • Pour the mixture out, and mould into your preferred shape. • Leave to dry out. This will take a while…
What to do with your plastic • Once your mixture has dried out, attach a magnet to the back with some superglue to create a fridge magnet!