In the 1960s movie classic, “The Graduate,” Dustin Hoffman, playing a recent college grad, is cornered by a middle-aged man who tells him the word for the future: plastics.
Today that word might well be bioplastics. As part of a growing global trend, plastics made from plant materials—biodegradable plastics, or bioplastics—are being used for everything from snack chip bags to makeup packaging, disposable cups, and food containers.
Companies including Cargill Inc.’s NatureWorks LLC, Proctor & Gamble Co., Johnson & Johnson, Inc., and Paper Mate have all introduced products that incorporate plant-based packaging instead of petroleum-based plastics. And Brazilian chemical firm, Braskem SA has just launched the world’s largest biopolymer facility. All of this could prove to be a boon to the environment because most bioplastics are biodegradable so they can be composted rather than languishing in landfills for decades.
Two of the most promising types of bioplastics are made from fermented corn sugar. These include polylactic acid, or PLA, which is clear and costs about 20 percent more to use than petroleum-based plastic, and polyhydroxyalkanoate, or PHGA, which biodegrades even more quickly but costs twice as much as regular plastic. Overall, bioplastics can cost anywhere from ten percent to 100 percent more than traditional plastics, one of the reasons, experts say, that the market is still relatively small.
Another issue for bioplastics is in order for them to biodegrade properly they need air to decompose. If a biodegradable utensil lands in an airtight landfill rather than a compost heap, it can take years to degrade, and if moisture hits it, it will give off methane, the same greenhouse gas that regular plastics emit. And some bioplastics cannot be disposed of at recycling facilities or composting centers as PLA can’t be mixed into the current recycling system, and most composting facilities refuse to take any kind of plastic.
Still, many companies are developing products made from bioplastics to fill the green niche market. In October 2010, Metabolix, Inc. and Archer Daniels Midland Company announced their joint venture, Telles, had launched Mirel™ 3002, a high-performance, biodegradable alternative to conventional plastic made from fermented sugar.
Mirel is currently available for use in composting bags, food containers such as yogurt cartons and single-use or disposable food packaging, food storage containers, personal care products, and shipping and packing materials as well as Target gift cards and PaperMate pens. NatureWorks’ Ingeo™ bipolymer is also being used in food and beverage containers such as Coca-Cola fountain-soda cups. And Braskem is supplying Procter & Gamble with sugarcane-based bioplastic for use in packaging for shampoo and makeup that will be on the market next year.
In addition to making bioplastics from corn and sugar, other manufacturers are experimenting with algae, switchgrass, and potatoes.
Article by Julie Mitchell, appearing courtesy Celsias.