Shell for products
Crab shell material will be an alternative to plastic
Natalia Pelezneva, N+1
The Georgia Institute of Technology has created a transparent flexible material that in the future will be able to replace plastic packaging for products. The description of the development is published in the journal ACS Sustainable Chemistry & Engineering.
To create a flexible and durable material, the researchers combined two widely used biopolymers. Cellulose is one of the main components of plant cell walls, chitin is the main element of the solid exoskeleton of arthropods, including insects and crustaceans. The third necessary element for the creation of the material was polylactide, a biodegradable polymer that is produced from annually renewable resources, such as corn or sugar cane.
The new packaging is obtained from microscopic particles of both biopolymers: chitin nanofibers and cellulose nanocrystals. They are individually placed in water, creating two suspensions (liquids with suspended particles), then the solutions are sprayed in layers onto a polylactide base. Chitin fibers have a positive charge, and cellulose crystals have a negative charge, so the frozen layers "stick together", forming a durable material.
The researchers compared the new material with polyethylene terephthalate (PET), which is widely used in the production of plastic bottles and other types of packaging. Chitin film significantly better protected the contents from oxygen penetrating from the outside than PET: the final version of the new material turned out to be 67% less permeable. Scientists suggest that due to this feature, chitinous "plastic" will help preserve products better than standard packaging.
Now scientists are working on technologies that will make the new material more resistant to water vapor. The researchers also plan to find the cheapest way to obtain chitin.
Previously, researchers have created a packaging plastic that gives a light signal when food begins to deteriorate.
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