Researchers from the Tuskegee University in Alabama, US, have developed nanoparticles made of eggshells to increase the strength and flexibility of the biodegradable packaging material.
They have created the biodegradable packaging material that bends but does not easily break.
Following series of experiments with various plastic polymers, the research team involving Vijaya Rangari, graduate student Boniface Tiimob and colleagues at Tuskegee University developed a mixture comprising 70% polybutyrate adipate terephthalate (PBAT), a petroleum polymer, and 30% polylactic acid (PLA), a polymer derived from cornstarch.
In order to further enhance the material's flexibility, the team then created nanoparticles made of eggshells because they are porous, lightweight and composed of calcium carbonate, a degradable natural compound.
Initially, the shells were washed, ground up in polypropylene glycol and then broke down into nanoparticles, which are more than 350,000 times smaller than the diameter of a human hair, using ultrasonic waves.
At a later stage, a small fraction of these particles was infused into the PBAT and PLA mixture, in a laboratory study.
Based on the results, the researchers said that the addition of the tiny shards of eggshell made the mixture 700% more flexible than other bioplastic blends making the material ideal for use in retail packaging, grocery bags and food containers including egg cartons.
Rangari said: "We're breaking eggshells down into their most minute components and then infusing them into a special blend of bioplastics that we have developed
"These nano-sized eggshell particles add strength to the material and make them far more flexible than other bioplastics on the market.
"We believe that these traits-along with its biodegradability in the soil-could make this eggshell bioplastic a very attractive alternative packaging material."
The researchers are planning to present their work at the 251st National Meeting & Exposition of the American Chemical Society (ACS) scheduled to be held on 15 March in the San Diego Convention Center.
Image: Researchers used eggshell nanoparticles to increase strength and flexibility of the bioplastic material. Photo: courtesy of Credit: Vijaya Rangari/Tuskegee University.
