Carbon dioxide. Orange peels. Chicken feathers. Olive oil. Potato peels. E. coli bacteria. It is as if chemists have gone Dumpster diving in their hunt to make biodegradable, sustainable and renewable plastics. Most bioplastics are made from plants like corn, soy, sugar cane and switch grass, but scientists have recently turned to trash in an effort to make so-called green polymers, essentially plastics from garbage.

Geoff Coates, a chemist at Cornell, one of the leaders in the creation of green polymers, pointed to a golden brown square of plastic in a drying chamber."It kind of looks like focaccia baking, doesn't it?" Mr. Coates said. "That's almost 50 percent carbon dioxide by weight."