Compost heap for sugar-based plastic
25 Feb 2010 by Evoluted New Media
Recycling plastic through the household collection is common throughout Britain, but scientists have been working on a sugar-based biodegradable plastic which can be thrown on the compost heap.
Recycling plastic through the household collection is common throughout Britain, but scientists have been working on a sugar-based biodegradable plastic which can be thrown on the compost heap.
The polymer – made from lignocellulosic biomass from non-food crops – could be used for single use items like food packaging and other disposable plastic items and then composted at home.
Fast-growing trees and grasses, or renewable biomass from agriculture or food waste can be converted into sugars which can absorb water, and degrade into harmless products on the compost heap.
“Our key breakthrough was in finding a way of using non-food crops to form a polymer, as there are ethical issues around using food sources this way,” said Dr Charlotte Williams from Imperial College London.
The biopolymer is manufactured in a low energy, low water use process. Biopolymers are different to biorenewable plastics as they are made from naturally occurring polymers such as starch or cellulose.
The leading biorenewable plastic – polylactide – is formed in a high energy process requiring lots of water and use food crops such as corn or sugar beet.
“The development of the material is very promising and I’m optimistic that the technology could be in use within two to five years,” said Williams.
As well as its use in plastics, the biopolymer could also have various medical applications because of its ability to degrade. The polymer is non-toxic to cells and decomposes in the body to create harmless by-products so it could be used in tissue regeneration, stitches and drug delivery.
Almost 99% of plastics are made from fossil fuels, with around 7% of worldwide gas and oil resources consumed in plastic manufacture.
