Each year, thousands of tons of nylon end up in landfills. But small-scale experiments may offer big hope for efficient recycling of some types of the material.
Nylon-6, an artificial polymer used in carpets, clothing, and car parts, is made by chemically linking large numbers of molecules derived from a petroleum product called caprolactam. Current processes to break apart, or depolymerize, nylon-6 typically must take place at high temperatures and high pressures. The processes are also relatively inefficient, says Akio Kamimura, an organic chemist at Yamaguchi University in Ube, Japan.
On the other hand, incinerating the polymers in mixed trash can create prodigious amounts of toxic compounds (SN: 1/29/00, p. 70). That's why nylon-6 usually ends up in landfills. Each year in the United States alone, carpets containing about 500,000 metric t