Scientists have developed a packaging material made from chitin and cellulose. It will keep food fresh for longer than conventional plastic.
The Georgia Institute of Technology has created a transparent flexible material that in the future can replace plastic packaging for products. The development description was published in the ACS Sustainable Chemistry & Engineering journal.
To create a flexible and durable material, the researchers combined two common biopolymers. Cellulose is one of the main components of plant cell walls, chitin is the main element of the hard exoskeleton of arthropods, including insects and crustaceans. The third essential element to create the material was polylactide, a biodegradable polymer made from annually renewable resources such as corn or sugar cane.
The new packaging is made 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 layer-by-layer onto the polylactide base. Chitin fibers have a positive charge, while cellulose crystals have a negative charge, so the frozen layers "stick together" to form a durable material.
The researchers compared the new material to polyethylene terephthalate (PET), which is widely used in plastic bottles and other types of packaging. Chitin film significantly better protected the contents from oxygen penetrating from outside than PET: the final version of the new material was 67% less permeable. Scientists suggest that due to this feature, chitinous "plastic" will help preserve food better than standard packaging.
Scientists are now 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.
Researchers have previously created plastic packaging that lights up when food starts to spoil.