Foamed food trays made of polylactic acid (PLA) resin, the corn-based biopolymer, have a commercial toehold in Europe and are undergoing market tests here.

High expectations for biopolymers— an emerging class of materials derived at least in part from biological activity—are being tempered by the realities of the marketplace.

Plastics made from renewable carbon chains, not fossil carbon from oil or gas, are suddenly a solid commercial reality. The draw isn’t just “green” marketing, but the “green” of stable prices not linked to petrochemicals.

Recent news testifies to growing momentum for biopolymers derived from corn by bacterial fermentation: --As reported on p. 22, DuPont Co., Wilmington, Del., is developing engineering thermoplastics and TPEs derived in part from fermented corn sugar. --Mazda Motor Corp., Tokyo, and a Japanese consortium of other companies, universities, and research institutes developed a heat-resistant plastic consisting of 88% corn-based polylactic acid (PLA) and 12% petroleum-derived materials.