Houston—The same longevity that makes plastics desirous as a material draws the ire of environmentalists who decry the burgeoning amounts of the synthetic materials piling up in landfills. At the recent Society of Plastics Engineers (SPE) International Polyolefins Conference in Houston, TX (Feb. 21-24), Samuel Adams, senior VP of bio-tec environmental, promoted his company's solution to the problem, EcoPure, a specially designed additive that's mixed into plastics at low levels (0.7%, 1.0%, 1.5%) and "coats" a polymer's chains to make them attractive to microbes. The microbes can then release acid and move through the chains, feeding on their ends and allowing the material to biodegrade. Adams stressed that this occurs even in a landfill's anaerobic environment, pointing to test results utilizing the ASTM D5511-02 Anaerobic Digestion Test.
Once broken down, the resulting byproducts are carbon dioxide, methane, sugars, and biomass. The company is hoping to feed into the growing support of methane-capture operations at landfills, where off-gassed methane is captured and used for energy generation. Adams said that right now, there are 450 such projects in the U.S., with an additional 540 "candidate" landfills and potential sites, with existing facilities in every state in the union.
According to Adams, EcoPure is positioning itself as an alternative to oxo-degradable additives and starch-based resins, which both claim accelerated decomposition compared to standard resins. Adams said that unlike many oxo-degradable resins, EcoPure has no heavy metals, particularly cobalt, which often sees use. Where oxo-degradable additives require light, heat, mechanical stress, and moisture to degrade, and starch can need industrial composting facilities, EcoPure will break down plastic in a sun and oxygen-free setting. In addition, where starch-based materials don't allow regrind to be used, and oxo-degradable plastics can't be used with polypropylene, polystyrene, or polyethylene, EcoPure regrind can be reused and the additive works with a wide range of polymers. When plastics with the additive are recycled, Adams said the viscosity and molecular weight do not change.
Launched in 2005, with international patents recognized in 2007, Adams said EcoPure has made "millions of pounds of plastic biodegradable," with products containing its additives in retailers like Wal-Mart, Target, Walgreens, and Rite-Aid, among others. See our initial coverage here.