Memorial University Derives Biodegradable Plastic Alternative from Fish Waste

Concept: Researchers at Canada’s Memorial University of Newfoundland (MUN) have developed a greener alternative to plastic from fish waste which would otherwise be discarded. The fish oil-based polyurethane can replace traditional polyurethane in several applications ranging from construction materials to clothing and packaging.

Nature of Disruption: MUN produced biodegradable polyurethane using the oil extracted from the remains of Atlantic salmon, such as the heads, bones, skin, and gut. Oxygen has been added to the extracted unsaturated oil to create epoxides, which are like the molecules found in epoxy resin. They linked the resulting molecules together with nitrogen-containing amines or amino acids after reacting these epoxides with carbon dioxide to form the new compound. MUN claims that environmentally friendly polyurethane does not have a fishy odor. It also investigated the degradation process of the biodegradable plastic by soaking the fragments in water and adding lipase, an enzyme capable of breaking down fats like those found in fish oil, to speed up the process. The plastic, after being immersed in plain water, started to exhibit signs of microbial growth on all the samples, which indicated that it is degradable. Some experiments suggest that amino acids like histidine and asparagine, which are easily accessible and naturally occurring, could replace the amine extracted from cashew nutshells that MUN formerly used. Moreover, fish waste can be easily sourced as salmon farming is a big industry on the coast of Newfoundland where the university is situated.

Outlook: The conventional process to produce polyurethanes is subject to serious environmental and safety issues as they are obtained from crude oil and very slow to break down. Given more than half the weight of a fish is often discarded as waste, the idea to process fish waste into biodegradable plastic seems wanting for environmental sustainability. Researchers at MUN presented their findings at the American Chemical Society’s spring meeting in 2021. They intend to keep studying the compound to understand how it could be used in real-world applications like packaging and manufacturing cloth fibers, among others.