Researchers at the University of Washington have created new bioplastics that degrade at the same rate as a banana peel in a backyard compost bin.

Derived entirely from powdered blue-green cyanobacteria cells called spirulina, both heat and pressure were applied to transform spirulina powder into assorted shapes. The researchers suggest that this is the same processing technique used to create conventional plastics and the spirulina-derived bioplastics reportedly have similar mechanical properties to single-use, petroleum-derived plastics.

Source: University of Washington

“The bioplastics we have developed, using only spirulina, not only have a degradation profile similar to organic waste, but also are on average 10 times stronger and stiffer than previously reported spirulina bioplastics. These properties open up new possibilities for the practical application of spirulina-based plastics in various industries, including disposable food packaging or household plastics, such as bottles or trays."

The researchers explained that they also selected spirulina to create bioplastics because spirulina cells reportedly sequester carbon dioxide as they grow, thereby making this biomass a carbon-neutral — or potentially carbon-negative — feedstock for the manufacture of plastics.

Further, the team noted that spirulina has fire-resistant properties and will self-extinguish when exposed to fire. As such, the researchers suggest that the material could be appropriate for applications such as plastic racks used in data centers where they would be exposed to high temperatures and where traditional plastics might fail due to their flammability.

Despite the mechanical strength and biodegradability of the material, the University of Washington team notes there are still challenges to overcome for scaling the material up for industrial use. Namely, the spirulina-based material is brittle and sensitive to water.

The spirulina-based bioplastic is detailed in the article, Fabricating Strong and Stiff Bioplastics from Whole Spirulina Cells, which appears in the journal Advanced Functional Materials.