Could corn-derived chemical replace BPA in polycarbonate and epoxy resins?
Published: August 16th, 2010
Archer Daniels Midland Co. (ADM) now offers a corn-derived chemical that it says is a potential alternative to the petroleum-based bisphenol A (BPA) in plastics and other applications. Isosorbide, which will be sold under ADM's line of Evolution Chemicals, can be marketed as "safe and renewable," according to ADM. BPA has come under consumer attack, retail bans, and regulatory examination for its alleged health impacts and "estrogen-mimicking" activity. The public outcry has all but driven polycarbonate (PC), which uses BPA as a key building block, from a variety of former strong holds, particularly in food- and beverage-contact applications like baby bottles and reusable sports bottles.
ADM describes isosorbide as a versatile ingredient with potential application in polyesters for inks, toners, powder coatings, packaging, durable goods; polyurethanes for foams and coatings; polycarbonates for durable goods and optical media; epoxy resins for paints; and detergents, surfactants, and additives for personal care and consumer products. ADM currently offers isosorbide in a technical grade that's 97% pure, as well as a polymer grade that's 99% pure.
In a May 19 presentation at the BMO Capital Markets 2010 Agriculture Protein & Fertilizer Conference, ADM said it was "investigating economical production methods for isosorbide for applications in plastics." The company described its current isosorbide output as coming from a pilot-scale line. Among the various products that ADM derives from corn, isosorbide comes from the liquid and crystalline sorbitol stream, which also produces propylene and ethylene glycol.
This National Academy of Engineering report, Applications of Corn-based Chemistry, laid out the potential applications of isosorbide, noting that The Iowa Corn Promotion Board, the U.S. Dept. of Agriculture, the U.S. Dept. of Energy, and the New Jersey Institute of Technology had begun work to "identify and assess potential polymer applications for isosorbide."
The paper noted that isosorbide diglycidyl ether resins could replace BPA epoxies used to line food and beverage cans, while isosorbide and dianhydroiditol PC could be used as molding plastics with high glass-transition temperature, transparency, and UV-resistance.—firstname.lastname@example.org