Eggshells are both marvels and afterthoughts. Placed on end, they are as strong as the arches supporting ancient Roman aqueducts. Yet they readily crack in the middle, and once that happens, we discard them without a second thought. But now scientists report that adding tiny shards of eggshell to bioplastic could create a first-of-its-kind biodegradable packaging material that bends but does not easily break.
The researchers present their work today at the 251st National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world’s largest scientific society, is holding the meeting here through Thursday. It features more than 12,500 presentations on a wide range of science topics.
“We’re breaking eggshells down into their most minute components and then infusing them into a special blend of bioplastics that we have developed,” says Vijaya K. Rangari, Ph.D. “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.”
Worldwide, manufacturers produce about 300 million tons of plastic annually. Almost 99 percent of it is made with crude oil and other fossil fuels. Once it is discarded, petroleum-based plastics can last for centuries without breaking down. If burned, these plastics release carbon dioxide into the atmosphere, which can contribute to global climate change.
As an alternative, some manufacturers are producing bioplastics — a form of plastic derived from cornstarch, sweet potatoes or other renewable plant-based sources — that readily decompose or biodegrade once they are in the ground. However, most of these materials lack the strength and flexibility needed to work well in the packaging industry. And that’s a problem since the vast majority of plastic is used to hold, wrap and encase products. So petroleum-based materials continue to dominate the market, particularly in grocery and other retail stores, where estimates suggest that up to a trillion plastic bags are distributed worldwide every year.
To find a solution, Rangari, graduate student Boniface Tiimob and colleagues at Tuskegee University experimented with various plastic polymers. Eventually, they latched onto a mixture of 70 percent polybutyrate adipate terephthalate (PBAT), a petroleum polymer, and 30 percent polylactic acid (PLA), a polymer derived from cornstarch. PBAT, unlike other oil-based plastic polymers, is designed to begin degrading as soon as three months after it is put into the soil.
This mixture had many of the traits that the researchers were looking for, but they wanted to further enhance the flexibility of the material. So they created nanoparticles made of eggshells. They chose eggshells, in part, because they are porous, lightweight and mainly composed of calcium carbonate, a natural compound that easily decays.
The shells were washed, ground up in polypropylene glycol and then exposed to ultrasonic waves that broke the shell fragments down into nanoparticles more than 350,000 times smaller than the diameter of a human hair. Then, in a laboratory study, they infused a small fraction of these particles, each shaped like a deck of cards, into the 70/30 mixture of PBAT and PLA. The researchers found that this addition made the mixture 700 percent more flexible than other bioplastic blends. They say this pliability could make it ideal for use in retail packaging, grocery bags and food containers — including egg cartons.
Learn more: Eggshell nanoparticles could lead to expanded use of bioplastic in packaging materials
The Latest on: Bioplastic
[google_news title=”” keyword=”bioplastic” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Bioplastic
- Best Antivirus Software for 2024on May 4, 2024 at 11:00 pm
Clifford is a managing editor at CNET, where he leads How-To coverage. He spent a handful of years at Peachpit Press, editing books on everything from the first iPhone to Python. He also worked at ...
- Bird flu virus found in grocery milk as officials say supply still safeon April 23, 2024 at 5:10 pm
a finding that does not necessarily suggest a threat to human health but indicates the avian flu virus is more widespread among dairy herds than previously thought, according to two public health ...
- Man who caught virus from a monkey in a critical condition – B virus explainedon April 16, 2024 at 4:33 am
Colin Michie does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...
- Hepatitis B Virus/Hepatitis C Virus Coinfection: Epidemiology, Clinical Features, Viral Interactions and Treatmenton April 13, 2024 at 5:00 pm
Because of the shared modes of transmission, hepatitis B virus (HBV)/hepatitis C virus (HCV) coinfection is not uncommon in highly endemic areas and among subjects with a high risk of parenteral ...
- Bird flu detected among chickens in Texas and Michiganon April 12, 2024 at 4:16 am
Ca-Maine Foods, largest fresh egg producer in US, temporarily halts production at one Texas facility after discovering virus Avian influenza has been detected among chickens in Texas and Michigan ...
- A Random Influx of DNA from a Virus Helped Vertebrates Become So Stunningly Successfulon April 11, 2024 at 5:00 pm
Retroviruses such as the HIV virus carry out this genetic hacking by reversing the sequence of the gene readout. They inject their RNA into the cells they infect, which serves as the code to make ...
- askST: What is the B virus and what threat does it pose to humans?on April 11, 2024 at 12:37 pm
SINGAPORE – A 37-year-old man from Hong Kong is in critical condition, having tested positive for the B virus after he was bitten by monkeys while on a hike. On March 21, the man was admitted to ...
- NIPAH VIRUSon April 9, 2024 at 3:39 pm
The state government has strengthened measures to prevent the spread of infection after two deaths were confirmed in Kozhikode district due to the Nipah virus. Kerala government on Thursday ...
- Measles outbreak in Chicago: What to know about the viruson March 27, 2024 at 9:50 am
Though most vaccinated people have close to zero chance of contracting the virus, here’s what to know about the disease. Yes, they do. In fact, measles, which was considered eliminated in the ...
- Inside the Coronaviruson February 3, 2024 at 9:56 am
We show how the immune system would normally attempt to neutralize virus particles and how CoV-2 can block that effort. We explain some of the virus's surprising abilities, such as its capacity to ...
via Bing News