A team of scientists from the United States, China, and Saudi Arabia has developed a new kind of plastic which they claim can be recycled an infinite number of times.
Most plastics are non-biodegradable, leading to millions of tons of plastic waste collecting in landfills and oceans. As most of these plastics degrade when melted and broken down, they are not suitable for recycling.
According to the study published in the journal Science Advances, the new plastic, called PBTL, is made from chemical building blocks called bicyclic thiolactones. No matter how many times PBTL is recycled, it maintains its original qualities.
The researchers believe that PBTL could be used to make car parts or construction materials and help reduce millions of tons of plastic that pollute the environment every year.
Large molecules called polymers constitute plastic. These polymers are further made up of simpler compounds called monomers.
The new plastic is prepared using a bridged bicyclic thiolactone monomer from a bio-based olefin carboxylic acid. To test its durability, the researchers recycled a batch by melting it down at 212 degrees Fahrenheit for 24 hours in the presence of a catalyst, reported Daily Mail.
Then, the researchers used the resulting monomer to make a new batch of PBTL, which had the same strength as the original. The team said that this process could be repeated over and over, possibly indefinitely.
"The failure to address end-of-life issues of today's plastics has not only accelerated the depletion of finite natural resources but also caused severe worldwide plastics pollution problems and resulted in enormous energy and materials value loss in the global economy," the study said.
"To address this global challenge, the design of next-generation polymers must consider their afterlife issues and establish closed-loop life cycles toward a circular economy," it added.
However, one drawback of PBTL is that it cannot be recycled with other kinds of plastics. In order to recycle it, it has to separated in recycle bins and waste centres.