International. A team of international scientists has found an eco-friendly way to produce aromatic compounds that show good UVA and UVB absorbance by using cashew peels (also known as Indian walnut or cashew), a waste material.
The team of "green chemists" at the University of the Witwatersrand, along with colleagues from universities in Germany, Malawi and Tanzania, are working on techniques to produce useful wood compounds and other waste from fast-growing inedible plants, through a chemical process. called xylochemistry (wood chemistry).
By using cashew shells, the team has produced new aromatic compounds that show good absorption of UVA and UVB rays, which can be applied to protect humans, livestock, as well as polymers or coatings from the sun's harmful rays. The research has just been published as the cover story of the European Journal of Organic Chemistry.
To mitigate UV damage, organic and inorganic compounds are used as UV filters. Ideal organic UV filters show high UV absorption of UVA rays (in the region ranging from 315–400 nm) and UVB rays (280–315 nm). An important family of UV-absorbing molecules is derived from aromatic compounds known as phenols, which contain a hydrogen-bound hydroxyl group that plays an important role in dissipating the absorbed energy.
For example, an organic compound known as oxybenzone is a common ingredient that has also been added to plastics to limit UV degradation. In addition to their petrochemical origin, one of the main drawbacks of current UV protection agents is their negative effect on aquatic ecosystems associated with poor biodegradability.
As a result, there is increasing attention from regulatory bodies and stricter regulations are being applied on the production of sunscreen products.
Producing New CNSL UV Absorbents
"With current concerns about the use of fossil resources for the chemical synthesis of functional molecules and the effect of current UV absorbers on sunscreens in the ecosystem, we seek to find a way to produce new UV absorbers from cashew shell liquid (CNSL) as an inedible bio-renewable carbon resource, "we seek to find a way to produce new UV absorbers from cashew shell liquid (CNSL) as an inedible bio-renewable carbon resource." says Professor Charles de Koning, from the Wits School of Chemistry and lead author of the paper, together with Till Opatz from Johannes Gutenberg University in Mainz, Germany.
"Cashew shells are a waste product in the cashew growing community, especially in Tanzania, so finding a useful and sustainable way to use these waste products can lead to completely new and environmentally friendly ways to do things."
The team has already filed a patent application to commercialize the process in South Africa.
Data Source Provider: University of the Witwatersrand.