The Co-op stopped using these bags following growing concerns over oxy-biodegradable plastics. To transform corn into plastic , corn kernels are immersed in sulfur dioxide and hot water, where its components break down into starch, protein, and fiber.
Bioplastics were mainly developed in an effort to find a replacement for conventional plastics whose problems include:. Discarded plastics are a big cause of pollution , cluttering rivers , seas, and beaches, killing fish, choking birds, and making our environment a much less attractive place.
To stop this happening, plastics manufacturers generally introduce extra stabilizing chemicals to give their products longer life. First, plastic that's recycled is generally not used to make the same items the next time around: A recipe for PLA bioplastics Take some corn kernels lots of them.
If bioplastic contaminates recycled PET polyethylene terephthalate, the most common plastic, used for water and soda bottles , for example, the entire lot could be rejected and end up in a landfill. Nature Chem. Department of Agriculture is developing a biodegradable and edible film from the milk protein casein to wrap food in; it is 500 times better at keeping food fresh than traditional plastic film.
Buy your fruit and vegetables loose, avoiding the extra plastic on pre-packaged items.
Some will break down only at high temperatures in industrial-scale, municipal composters or digesters, or in biologically active landfills also called bioreactor landfills , not on ordinary home compost heaps or in conventional landfills. PLA, for example, produces almost 70 percent less greenhouse gases when it degrades in landfills. Some need exposure to UV ultraviolet light or relatively high temperatures and, in some conditions, can still take many years to break down.
Recycled plastics One neat solution to the problem of plastic disposal is to recycle old plastic materials like used milk bottles into new ones such as items of clothing.
Recycling, though valuable, is only slightly better than throwing something away: The old grocery store bag on the left has been exposed to the light for a few months and has already started to turn yellow compared to the new bag on the right. More to explore on our website...
Is sugar the new plastic? Greenhouse gas mitigation for U. PLA polyactic acid is typically made from the sugars in corn starch, cassava or sugarcane. To most people, PLA looks very similar to PET polyethylene terephthalate but, if the two are mixed up in a recycling bin, the whole collection becomes impossible to recycle.
The New York Times, February 9, 2012. When some biodegradable plastics decompose in landfills, they produce methane gas.
The cornstarch molecules they contain slowly absorb water and swell up, causing them to break apart into small fragments that bacteria can digest more readily. Used to make bags, containers, cutlery, water and shampoo bottles, this bioplastic is compostable, marine degradable meaning that if it ends up in the ocean, it can serve as fish or bacteria food and has no toxic effects.The Shocking Truth About Biodegradable Plastics
Public pressure to clean up has produced plastics that seem to be more environmentally friendly. Thank you for visiting nature.