Little eggshell helps bioplastics transform into ideal packaging materials

【China Packaging News】 Rangar's research team at Tuskegee University is ingenious, adopting eggshell nanoparticles to toughen bioplastics. The small eggshells truly transform bioplastics into ideal packaging materials. In addition to bioplastics, the Rangari team is working on the use of eggshell nanoparticles to accelerate wound healing, bone regeneration, and drug delivery.

The eggshell is a peculiar material with a strong tip, but it is easy to crack from the middle. Once the eggshell cracks, we will abandon it without hesitation. The scientific report pointed out that the addition of small eggshell fragments to bioplastics can create the first biodegradable packaging material that is flexible but not easily broken. At the 251st American Chemical Society International Fair, researchers reported on their results.

Dr. Vijaya K. Rangari said: " We are focusing on breaking down the eggshell into very small components and adding it to the bioplastics we produce. These nano-sized eggshell fragments will increase the strength of the material Make it easy to circulate in the market. We believe the above advantages and its biodegradability will make eggshell bioplastics a very attractive packaging material. "
Producers worldwide produce approximately 300 million tons of plastics annually . Almost 99% is based on fossil fuels such as crude oil. Once these petroleum-based plastics are discarded, they cannot be degraded for hundreds of years. If it is burned, it will release carbon dioxide that causes the greenhouse effect to the environment.

Some manufacturers are producing a bioplastic that is easily degradable in the soil. This plastic comes from corn starch, sweet potatoes and other renewable plant resources. However, the strength and toughness of the above-mentioned production materials are not large enough to be used in the packaging industry. Therefore, petroleum-based materials still dominate the market, especially in grocery stores and retail stores that supply countless plastic bags.

In order to find a solution, Rangari and Boniface Tiimob of Tuskegee University and colleagues conducted research using a variety of polymers. In the end, they found a mixture containing 70% PBAT and 30% PLA . Unlike other petroleum-based plastics, by design, PBAT can begin to degrade in the soil in three months.

Although this mixture has many properties that researchers have been struggling to find, they still hope to further enhance the toughness of the material, so eggshell nanoparticles came into being. They chose the eggshell because it is porous, lightweight, and made of calcium carbonate, a natural compound that degrades easily.

By crushing clean eggshells in polypropylene glycol and sonication, the researchers obtained eggshell nanoparticles with a size of one third of the hair diameter . Then they added these small particles to the mixture of PBAT and PLA , and then found that the bioplastics with eggshell fragments were 7 times more tough than ordinary bioplastics . They said that such a flexible material is the ideal packaging material for retail stores, grocery stores and food containers.