Converting cashew nut shells into sunscreen
A team of international scientists has found an environmentally friendly way of producing potential sunscreens by using cashew nut shells, a waste material.
The University of the Witwatersrand, along with Universities in Germany, Malawi and Tanzania, has produced new aromatic compounds using cashew nut shells that show good UVA and UVB absorbance, which may be applied to protect humans, livestock, as well as polymers or coatings from harmful rays from the sun.
UV rays are damaging to most materials, with its effects leading to the discoloration of dyes and pigments, weathering, yellowing of plastics, loss of gloss and mechanical properties, while it can lead to sunburn, premature aging and even the development of potentially lethal melanomas in both humans and animals.
One important family of UV absorber molecules are derived from aromatic compounds known as phenols. An organic compound – oxybenzone is a common ingredient that has also been added to plastics to limit UV degradation. Due to their petrochemical origin and negative effect on aquatic ecosystems associated with a poor biodegradability. there is growing attention from regulatory bodies and stricter regulations are being enforced.
While the new UV absorbers from cashew nut shell liquid (CNSL) is a non-edible, bio renewable carbon resource. The team has already filed a patent application in order to commercialise the process in South Africa.
Source – Science daily, 15 Aug, 2019