Developments to Watch
PLASTICS THAT BREAK DOWN--WITHOUT BREAKING THE BANK
Plastics have such a bad name in some circles that packaging makers would welcome a biodegradable plastic--as long as it didn't cost much more than regular plastics. There is already a proven material--absorbable sutures made from lactic acid--but that plastic costs as much as $250 per pound.
Now, researchers at Battelle Memorial Institute in Columbus, Ohio, have modified the manufacturing process so that they can produce lactic-based plastics for $1 to $2 a pound, much closer to the cost of commodity plastics, which sell for less than $1 per pound. Their process yields materials--with a wide range of properties from brittle to stretchy--that are 100% degradable by microbes in the soil. They degrade with or without air in six months to five years--and can have a shelf life of up to two years. Raw materials for the plastic are readily available from food wastes such as potato peelings or residue from cheese production. They could be used to make all kinds of disposable containers.EDITED BY EMILY T. SMITH