|Adored, Deplored and Ubiquitous [NYT]|
By NATALIE ANGIER
Come next Tuesday, in a move flagrantly timed to coincide with Earth Day, the Whole Foods supermarket chain will no longer offer its customers the plastic bag option. Seeing that “it can take more than 1,000 years for a plastic bag to break down in a landfill” and that “in the U.S. alone, about 100 billion plastic bags are thrown away each year,” the company said it could not in good conscience contribute to the crisis.
Bravo. Now tell me this: What am I supposed to line my garbage cans with? I always use plastic supermarket bags, and the Whole Foods ones were by far my favorites — roomy and springy enough to hold a lot of sodden waste without fear of breakage, always a plus when one is disposing of, say, fish skins or cat litter. So if I have to buy plastic bags by the box, that’s better for the environment how? Forget about paper bags for this purpose. When we were growing up in the Bronx, my older brother recently reminded me, we lined our garbage can with newspapers, a solution satisfactory to none but the roaches.
A century ago, the Belgian-born chemist Leo Hendrik Baekeland ushered in a materials revolution with his invention of Bakelite, a synthetic resin that was molded into radio cases, lamps, buttons, dressers and other Antiques Roadshow reliables. We have been emotional bobbleheads about plastics ever since. We adore plastics for their versatility, lightness, strength and affordability, and it seems we can’t get enough: the United States produced 6.5 billion pounds of raw plastic in December alone, up 2.3 percent from a year earlier. We deplore plastics for being cheap petroleum products and fear we’ll never get rid of them.
Yet scientists point out that the class of substances lumped together under the plastics postmark is so broad and diverse that to condemn or condone them categorically makes no sense. Moreover, the field is evolving rapidly, as researchers strive to spin plastics from renewable sources like sugar cane and grass clippings in lieu of fossil fuels, and to outfit their creations with the chemical grace to decay once discarded. “We can do a lot of interesting things, but there’s more research that needs to be done,” said James A. Moore, a professor of chemistry at Rensselaer Polytechnic Institute. The biggest catch in reaching the new, greener stage of the plastics age, he said, “is that we have to accept that it’s going to cost money.”
Glancing around my office, I see how difficult it would be for me to live plastic-free. I’m typing on a computer keyboard made partly of molded polyvinyl chloride, which also serves as the source material for that ultimate plastic item, the credit card. Some components of the two black telephones on my desk are built of injection-molded acrylonitrile butadiene styrene, a material that has the strength and toughness to resist cracking when dropped, and hence is also used in motorcycle helmets and luggage. My earrings are made of Lucite, a lightweight acrylic that is embarrassingly popular among jewelry makers now. A cottontop tamarin doll on my bookcase stares down through beady brown eyes — probably acrylic as well — and its chirpy fake fur is woven from polyester fibers. My desk and bookshelves are made of particle board, a composite of wood chips and a plastic resin. Lining my wastebasket is, yes, a plastic shopping bag, this one from Safeway, and like most plastic bags it’s made of polyethylene, “the largest-volume plastic” of all, said Richard A. Gross, a professor of chemistry and biology at Polytechnic University in Brooklyn. In fact, all my views arrive as though Saran-wrapped, for I’d be blind without the blend of plastics from which my rigid gas permeable lenses are cast.
Uniting these and the hundreds of other plastics that pad our mattresses, elasticize our comfort-fit jeans, suture our wounds, plug our dental cavities, encapsulate our pills, replace our lost limbs, lighten our cars and jets and crisscross our Kevlar vests is the state of being a synthetic polymer. The term polymer refers to any long molecular chain made up of smaller chemical units, or monomers, which polymer chemists habitually compare to beads on a necklace or, when they’re going out for a nice dinner, to pearls on a strand.
Life abounds with polymers. DNA, proteins and starches are polymeric molecules, all concatenations of smaller molecules. Plastics are just polymers in which humans, rather than nature, string the beads. Granted, we’re still pretty crude jewelers by comparison. The synthetic polymers in the plastic skin of a garbage bag, for example, are monotonous skeins of a single type of chemical bauble, ethylene, while the protein polymers in a fish’s skin are intricate arrays of as many as 20 distinct amino acids, the monomers of which proteins are built.
What’s more, whereas nature knows how to make thousands of different polymers and can make them the same length and shape every time, chemists have yet to master such fine control over their product line. “The typical way a polymer is made is you throw your monomers into a big pot and let them all react, as opposed to building them up one piece at a time the way the body does,” said Elliot P. Douglas, an associate professor of materials science and engineering at the University of Florida. “When we make a mixture, it’s a mixture of all different lengths.”
But our bodies and our plastics are by no means antithetical beasts. The polymers in both cases tend to feature a lot of carbon atoms, carbon having a readily linkable structure that makes it an ideal component of life — of the lives we live now, and of the ancient, squeezed and subliminated lives that constitute fossil fuels. It’s also an ideal constituent for monomers you want to toss together into your pot and have a product with useful properties come out the other side, like stretchiness, stickiness, ductility, disdain for electrical flow.
The reason petroleum so often serves as the foundation for plastics production is that it offers an ultraconcentrated source of carbon, but carbon is carbon and with the right manipulations other handier biosources like lawn litter will do. Add chlorine to your carbon backbone for hardness and heat resistance. Tack little methyl groups to the carbon backbone for durability, compactness and a ropy indifference to chemical abuse. Extrude your melted mixture through die holes to form pipes, hoses, drinking straws and fibers. Inject it into moldings shaped like Barbie, Ken or a comb. Blow it out like a balloon and you’ve got a new bag. When you’re done, hand it over: I will put it to use.