CO2-based plastic flagged up as bisphenol A alternative

A breakthrough process that converts waste carbon dioxide into food packaging and coatings could also be used to replace bisphenol A (BPA) in the linings of food and drink cans, said Novomer, the company developing the technology.

The eco-friendly method to produce polymers and polyols has been “fully developed at pilot scale” company vice president business development Peter Shepard told FoodProductionDaily.com. The polymers are targeting flexible and rigid packaging applications – such as films, moulded containers and paper coatings. The polyols are being targeted applications in water and solvent based coatings and composites.

BPA replacement

While many of the polyols are being aimed at the industrial sectors, the company identified at least one application that could mark a major breakthrough the food packaging industry as a replacement for bisphenol A (BPA) in can linings.

“We believe our polyol technology may offer a replacement for epoxy in can linings,” said Shepard. “The advantage is our polyols do not contain BPA. The applications include two- piece cans – such as soda and beer - and three-piece cans for food.”

The company said it had “just begun the food contact notification process” with the Food and Drug Administration (FDA).

Rising consumer, scientific and political concern over the continued used of BPA in food contact materials on health grounds has triggered an intense search for alternatives. The North American Metal Packaging Alliance (NAMPA) said in May the canned food and drinks sectors were bowing to consumer pressure and seeking BPA replacers. Earlier this month, Heinz Australia said it would be phasing out BPA use in its baby foods and was actively trying to develop substitutes.

CO2 Process

The Novomer process uses a proprietary catalyst that enables the carbon dioxide to be inserted into an epoxide which forms a polymer, said Shepard. Using propylene oxide as an example, the chemical is placed into a reactor before the catalyst is added. The reactor is pressurised with CO2 – sourced from a gas or ethanol plant waste stream - which triggers the reaction.

The reaction occurs at low temperatures and pressures so it requires much less energy than traditional petroleum based polymers, added Shepard. “The energy required is 40-60 per cent less than petro-based materials and the carbon footprint is 50-70 per cent less than competing materials.”

The US firm has just received an $18m-grant from the Department of Energy to support the process scale-up and applications development of it CO2-based polymers and polyols. The cash injections was the second part of a funding programme that saw the government hand out $2.1m earlier this year to identify applications and develop plans for bringing the technology to pilot scale.