Chemical engineers at Iowa state university have sparked interest across the chemical industry with the development of a new nylon constructed from sugar. The discovery of a simple process to produce nylon from a sustainable resource has captured the imagination of many chemical market analysts and potentially could affect chemical prices for many oil-based compounds.
By combining a strain of genetically engineered yeast and an electrocatalyst, the projects lead authors, Zengyi Shao and Jean-Philippe Tessonnier (pictured), assistant professors of chemical and biological engineering at Iowa state university, have avoided many of the problems that previous research has hit upon.
Prior to the discovery, scientists combining biocatalysis and chemical catalysis to produce biorenewable chemicals suffered low conversion rates due to a residue of impurities that the biological process would leave behind, reducing the effectiveness of the chemical catalysts. This new process had no such drawbacks.
Shao and Tessonier have published their results in the periodical ‘Angewandte Chemie International Edition’, and also discussed their discovery with the online publication phys.org, which explained the new method as follows, “Here’s how their technology works: Shao’s research group has created genetically engineered yeast – ‘a microbial factory,’ she said – that ferments glucose into muconic acid. By applying metabolic engineering strategies, the group also significantly improved the yield of the acid. Then, without any purification, Tessonnier’s group introduced a metal catalyst – lead – into the mixture and applied a small voltage to convert the acid. The resulting reaction adds hydrogen to the mix and produces 3-hexenedioic acid.
After simple separation and polymerization, the engineers produced biobased, unsaturated nylon-6,6 which has the advantage of an extra double bond in its backbone that can be used to tailor the polymer’s properties.”
The work at the university, which is also affiliated to the National Science Foundation Engineering Research Center for Biorenewable Chemicals (CBiRC) has many advantages as it is requires no additional chemical supplements, is carried out at room temperature and pressure, and uses a cheap and abundant metal, instead of a precious element such as platinum. All other compounds involved are produced from water.
Given this simplicity, Shoa and Tessonier are confident of the ability to upscale the process. If this happens then the discovery is certain to affect many parts of the chemicals industry. Not only because of the non-oil based production of a nylon, but because, to use Shao’s own words, the process avoids the disruption of, “a gap between biological conversion and chemical diversification. [By bridging the] gap with a hybrid fermentation and electrocatalytic process the engineers have opened the door to the production of a broad range of compounds not accessible from the petrochemical industry.”
And that could change the chemicals market forever.