New Bio Chemicals Target Phthalate Plasticizer Replacement

In the global race to develop sustainable feedstocks that replace petrochemicals, a Minnesota company is quietly pounding a major stake in the ground.

Segetis, founded in 2007, has developed new-to-the-world molecules based on levulinic acid esters made from corn cobs and bio-based hydroxyl compounds.

The new chemical building blocks are called levulinic ketals and can be used to make a variety of products, including solvents, plasticizers and polyols for polyurethane foams.

"We expect to have commercial products in each of those groups by the end of 2011," says Snehal Desai, business vice president at Segetis.

Drum loads of monomers are now being delivered to development partners from a semi-works production facility built in Minneapolis in 2009. Capacity at the plant is 250,000 pounds per year. Segetis has commissioned construction of a toll manufacturing plant in the Midwest that will be online early next year. Commercial products will enter the market, starting with solvents. Polyols will be last because of significant functional testing requirements.

For now, Segetis is sourcing levulinic acid from China, but longer term the company may use wood residue from pulp and paper production as a feedstock.

In April, PolyOne Corp., a major compounder, announced an agreement with Segetis to explore the development of bio-derived plasticizers for use in bio-based polymers. Another potential outcome could be the replacement of phthalate plasticizers which make PVC and other plastics flexible. Two specific types of phthalate plasticizers have been under fire over concerns about exposure to children. "We are working on a straight-up replacement of phthalates in PVC," says Desai. One advantage of the ketal monomers is that they appear to attach firmly to the PVC molecule. Another is their all-natural origins.

Another major opportunity for the new chemistry is the manufacture of polyols which combine with iscoyanates to produce polyurethane.

"The polyols made from our ketals have an inherent rigidity in their backbone structure," says Desai. "As a result it is possible to reduce the isocyanate levels to obtain similar levels of properties. So the use of our monomers is as much a performance play as it is a carbon footprint play."

Use of agricultural feedstocks has been a hot story in polyurethane foams for the past two years.

There are more than two million Ford vehicles on the road today with bio foam content. Ford's use of bio foam has helped the company reduce its petroleum oil usage by more than three million pounds annually and carbon dioxide emissions by 11 million pounds. Ford's biofoam is based on soy feedstock in a program partially funded by the United Soybean Board, a U.S. farmer-led organization.

Soy-based foam reportedly costs less than petrochemical-based foam, helping fuel the explosion in its use the past two years.

Desai says the polyols produced by Segetis are expected to cost about the same as polyols made from petroleum resources. But the economics for formulators will be improved through reduced use of isocyanates. "We believe there is a total cost picture that is favorable for the ketal chemistry," says Desai.

Segetis was founded by Sergey and Olga Selifonov, a Russian couple now living in the Minneapolis area.

Their patents disclose a series of glycerol-derived compounds that are based on the formation of a ketal with the ketone group of levulinic acid. Glycerol-levulinate ketal compounds can be produced by reacting approximately one molar equivalent of glycerol with approximately one molar equivalent of levulinic acid in the presence of an acid catalyst, and under conditions allowing for removal of water, typically by distillation.

Their process is less costly than some competing bioplastic processes that require fermentation.

Longer range, Segetis may attempt to develop other plastics with its monomer technology. For example, levulinic acid is a potential precursor to polyamide-like polymers and synthetic rubbers. One of the investors in Segetis is DSM, a Dutch producer of polyamides (nylons) and other high-performance plastics.