When most people think about the polluting effects of petroleum, they'll likely conjure up images of smog emitting from the exhaust pipes of gas-guzzling trucks, but automobiles are only one part of the oil-pollutant equation. Most plastics—from the disposable fork to the Lego piece—are also made out of fossil-fuels.
As electric-car manufacturers like Tesla make great strides in renewable energy on one front, companies like The Lego Group are doing their part to make make their industry eco-friendly. In 2010, plastics made up 2.7 percent of all petroleum consumption in the United States.
Last week, Lego announced plans to invest $150 million into finding a biodegradable material to replace the petroleum-based polymers that make up the miniature building blocks we all know and love.
The tens of billions of Lego pieces produced each year are made out of ABS—an acronym for acrylonitrile, butadiene, and styrene, three polymers synthesized from petroleum—which possesses unique qualities that have proved difficult to duplicate with bio-plastic substitutes.
Earlier attempts by Lego to replace ABS proved futile. For example, a polylactic-acid polymer made from corn lost its rigidity and shape a few weeks after being molded. Lego is redoubling its efforts, though, launching a sustainability center that will assemble a staff of over 100 chemists and other specialists in the material sciences.
The timing of Lego’s decision to become eco-friendly might suggest that biodegradable plastics is a relatively new area of research. In fact, experimentation with polymers synthesized from soybeans and other plants goes back 60 years, with interest waxing and waning with the rise and fall of oil prices.
“[Interest has] ramped up significantly in the past two decades,” said Marc Hillmyer, director of the Center for Sustainable Polymers at the University of Minnesota. “It’s been very active.”
Polylactic-acid polymers, synthesized from crops like corn and sugar-beets, have already found numerous applications, serving as the base material for disposable cutlery, plastic cups, and even apparel, so it wasn’t surprising that Lego sought to have it replace ABS.
“Polylactic-acid is one of the most successful bio-based plastic that’s been derived from biomass,” Hillmyer said.
Hillmyer was among a coterie of chemists who received a total of $20 million dollars from the National Science Foundation last year to research and develop eco-friendly plastics. In his lab, Hillmyer focuses on tweaking the structure of polylactic-acids and other bio-plastic polymers to make them compliant to commercial needs.
“One of the things we’ve been developing is a very tough version of polylactic-acid that don’t have some of the inherent qualities that other materials have,” he said.
Polylactic-acid has also been modified in the other direction, becoming soft and flexible enough in some variants to serve as photographic film.
To ensure that bioplastic will actually biodegrade, polymers are often stress-tested in model experiments for their susceptibility to hydrolysis and oxidation, with standards set by the ASTM International, a standards development organization.
Still, despite the existing body of research on bio-degradables, we’re only at the outset of the journey to wean ourselves of petroleum-based plastic. Almost everything around you that’s not made out of wood, metal, or glass is made of plastic—from the mouse you’re clicking on, to the armrest you’re leaning on, to the fan massaging your face with a breeze.
Let’s hope that oil prices stay high.
