Dream of plastics from carbon dioxide is a reality.

Jun 01, 2010

 Zhang, Y and J Young Gerentt Chan. 2010. Sustainable chemistry: imidazolium salts in biomass conversion and CO2 fixation. Energy and Environmental Science http://dx.doi.org/10.1039/b914206a.


Certain classes of organic molecules can be instrumental in both capturing carbon dioxide from the air and incorporating it into new plastic materials, which could lessen the need for raw petroleum.


(6-21-10 Corrections: The research studies mentioned in this summary were not conducted by the review paper’s authors, as implied in this summary. Instead, the authors were summarizing results of prior studies.)

(6-24-10 Editor's note: The paper's authors did not speculate about using the plastics made by this method to replace current polycarbonate plastics.)

Chemists have made progress in finding environmentally friendly ways to capture and reuse carbon dioxide (CO2), according to an article that reviews recent research in this field. Specifically, significant new advances have been made in the ability to absorb CO2 from the atmosphere and incorporate it into new raw materials – including which may include benign alternatives to BPA-based plastics.

Certain classes of organic molecules have been discovered to be instrumental in capturing carbon dioxide from the air and incorporating it into new plastic materials. This process eliminates petroleum as an input and generates more benign materials in the process.

In this and several other recent articles, researchers The review article's authors report how a class of chemicals – called “ionic liquids” – when combined with metal salts can efficiently capture and incorporate CO2 into chemicals, which can then be turned into a plastic. Such plastics that are created during the multistep process can contain about 40 percent by weight of incorporated CO2.

CO2 is an excellent chemical building block; it is renewable, abundant and considered environmentally friendly. Plants efficiently convert CO2 into food through photosynthesis. Scientists, however, have long struggled to reproduce this process at an industrial scale. Before recent advances, the methods that existed were very inefficient, rendering them economically unviable.

Two research groups may have stumbled on a The review article summarizes research studies that have identified a much more efficient method. Using chemicals called imidazoliums, combined with metal salts, chemists can create and N-heterocyclic carbenes (NHCs), researchers in Singapore report they were that are able to couple CO2 with molecules called "epoxides" to form polycarbonates – plastics used in everything from water bottles to compact disks.

Importantly, in addition to finding a new use for carbon dioxide, these polycarbonates do not contain bisphenol A. It turns out that while virtually all commercial polycarbonate plastics today are made using bisphenol A as the basic building block, there are alternatives, as the reported research demonstrates d by this research.

The imidazolium salts are stable chemicals that can repeatedly “grab” CO2 molecules and hand them over to be incorporated into bigger molecules. This makes them valuable in processes that convert CO2 to other chemical products as well. In addition, they are more benign and the reactions less severe than the metals typically used.

In sum, this the research reported in this review article demonstrates two significant advances, first, in demonstrably moving forward the capacity to harness and use CO2 in industrial applications, and second, in its successful application in developing a benign alternative to a problematic chemical currently used to make polycarbonate plastics.