The new type of bags have been developed by the University of Nottingham. The process can also be used to make packaging material for storing food. The main market will be North Africa, specifically Egypt where waste management is a major problem and recycling rates are low.
The bags are developed through nanotechnology by using the shells to form a biopolymer nanocomposite material. The shells are used to produce chitosan. This is an artificial polymer based on chitin. Chitin is the organic polymer that forms the crustacean shell. The material would be biodegradable and produced at a low-cost.
The process takes chitin and places it into acid. The acid hydrolysis strips out calcium carbonate. This is followed by the addition of then alkali, which generates long molecular chains which make up the biopolymer. The resultant chitosan flakes are dried and then dissolved into a solution. This is used to create a polymer film produced by conventional processing techniques. A further advantage with chitosan is that is possess antimicrobial properties.
The reason why an alternative based on shrimp shells is required, rather than established biodegradable goods, like those based on natural biopolymers, is because of the competition with food crops in terms of the available land. The use of shrimp shells also addresses a waste disposal solution for the millions of crustacean shells produced as part of the food production system. Many shells are simply dumped at illegal sites.
Behind the new bag is Dr. Nicola Everitt, who has undertaken the development with fellow researchers from from Nile University in Egypt. Speaking with Controlled Environments magazine, Dr. Everitt explains: “Non-degradable plastic packaging is causing environmental and public health problems in Egypt, including contamination of water supplies which particularly affects living conditions of the poor.”
As a future application, Dr. Everitt aims to use the new material for food packaging. This will take advantage of the antimicrobial properties. The research is continuing and the findings have yet to be published in a peer reviewed journal.
