Unzipped

Janice_Kaspersen_Blog

What if one morning the news contained, rather than more problems for you to contemplate, the solution to a longstanding dilemma? Thanks to researchers at the University of Illinois and elsewhere, we might have at least the beginning of an answer to the plastics problem.

All the editors here at Forester Media have dealt at different times with the question of plastics: How much of it ends up in the ocean, in our drinking water, and in our landfills. Because it doesn’t biodegrade, once plastic is produced it’s around virtually forever, slowly breaking down into smaller and smaller pieces that are easily ingested by birds, fish, and other marine life. Now, though, chemists have developed a workable way to make plastics break down into what appear to be harmless components.

Adam Feinberg, a chemist at the University of Illinois at Urbana-Champaign, has devised a way to make synthetic polymers—plastics—“unzip” into their component molecules when exposed to strong ultraviolet light. Other triggers for unzipping, such as heat, are also possible. This New York Times article explains the process in some detail. “The environmental effects of plastic buildup and the declining popularity of plastics have helped to spur chemists on a quest to make new materials with two conflicting requirements: They must be durable, but degradable on command,” says the article. “In short, scientists are in search of polymers or plastics with a built-in self-destruct mechanism.”

Marc Hillmyer of the Center for Sustainable Polymers at the University of Minnesota sums up the problem more simply: “The real trick is to make them stable when you’re using them, and unstable when you don’t want to use them.”

Although it might not be economically feasible to create single-use plastic items like shopping bags and drinking straws that are easily degradable, other plastic items—the article cites the polyurethane foams used in things like mattresses and car seats—are better candidates. Hillmyer has worked on a foam that is stable at room temperature and breaks down only if heated to temperatures of more than 400°F. He points out that for the process to work efficiently, companies would need to take responsibility for the entire lifecycle of their products—perhaps taking back the product, breaking it down, and creating something new from the same material. The challenge becomes a logistical as much as a technical one.

A future possibility, according to Elizabeth Gillies, a polymer chemist at Western University in London, ON, is using the technology to create specialized packaging that unzips itself exactly where and when its contents are needed, releasing them on demand. She mentions, for instance, containers that could be unzipped in the body to deliver a cancer drug at the site of a tumor or containers for fertilizer that could be unzipped at specific locations and times in the field. SW_bug_web

Comments
  • Jonathan McClelland.

    It seems to me that using uv or high heat just to degrade plastic is a energy intensive, w/o any useful byproduct created by the process. Wouldn’t it be better to just use plastics for applications where it can be a superior material to the alternatives? Charging for bags encourages people to BYO. Ziplocs can be reused many times. Beverage containers are reformulated into polypropylene clothing and other products. Plastic tool handles reduce electric shock and hand fatigue. Plastic isn’t inherently bad. Slothful use of anything leads to negative consequences.

    Reply

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