A US start-up company Novomer is developing biodegradable plastics made from carbon dioxide.

Environmentalresearchweb reports that the company, which recently received US$6.6 m in venture capital funding, claims that its plastics can contain up to 50% of the material by weight.

Carbon dioxide is very unreactive and chemists have in the past tried to make polymers using this cheap feedstock by combining it with epoxides. However, because of the unreactive nature of the gas, these reactions have had to take place at high temperature and high pressure and have resulted in a very low yield.

Novomer, however, has exclusive access to catalysis technology developed at Cornell University, US. Charles Hamilton, president of Novomer, told environmentalresearchweb: "We use the same materials - CO2 and epoxides - but our zinc-based catalyst works at room temperature, low p ressure and gives a high yield. Using this catalyst, we can make a range of non-degradable and biodegradable aliphatic polycarbonates for various uses."

The company is currently testing the biodegradability of its polymers and expects them to perform as well as other biodegradable polymers on the market, degrading in about six months under ideal conditions. "We can make polymers that are chemically identical to other biopolymers," says Hamilton. "But we do not use corn-based feedstocks so do not compete with food production." As well as carbon dioxide, the company uses carbon monoxide (CO) to make another class of polymer which also contain up to 50% by weight CO.

Currently, the company is still at the research stage of development and therefore does not yet use large quantities of carbon dioxide. However, Novomer plans to use its new investment to scale up manufacturing capacity. "In order to move to pilot-plant scale, we need to find reliable, high-pu rity sources of CO2," says Hamilton. "Perhaps next to a cement manufacturer or a hydrogen plant."

While Novomer‘‘s technology will use up large amounts of carbon dioxide during manufacture of the polymers, all of this will be re-released as the polymer degrades and is metabolized by bacteria. "While some may not see this as environmentally friendly, by using up to 50% CO2 in our polymers we have significantly reduced the amount of fossil fuel-based feedstock used to make the polymers," says Hamilton. "And by making the polymers biodegradable, we have reduced the amount of landfill." The company has not yet tested the biodegradability of its polymers but estimates, as with similar polymers on the market, that they will take about six months to degrade.