SCIENTISTS at the Colorado State University (CSU) have beaten other researchers in the race to develop a fully recyclable and biodegrable plastic, rendering petroleum-based polluting plastics obsolete.
The researchers also undercut the work of US biotechnologists who have been coaxing fungi to produce plastic sheets in a process called biomimesis.
This product could potentially reduce global pollution by preventing the dumping of nonbiodegradable plastics in sanitary landfills and the dumping grounds of computers and other gadgets in China, US, the Philippines and other countries.
In 2013 the European Union (EU) estimated that hard plastic formed a significant volume of the electronic waste (e-waste) that comprised 25 percent of the waste exported to Africa and Asia for recycling.
“The global volume of electronic waste is expected to grow by 33 percent in the next four years, when it will weigh the equivalent of eight of the great Egyptian pyramids, according to the UN’s Step initiative, which was set up to tackle the world’s growing e-waste crisis.
“Last year nearly 50 million metric tons of e-waste was generated worldwide—or about 7 kilograms for every person on the planet. These are electronic goods made up of hundreds of different materials and containing toxic substances, such as lead, mercury, cadmium, arsenic and flame retardants,” the Guardian of the United Kingdom reported on December 14, 2013.
Recycling plastics and other metals in Guiya, Guangdong, the biggest landfill for e-waste, has led to many cancer cases among the workers sifting through the materials in search of copper, gold, zinc, berylllium, tantalum and rare earths.
“Once in landfill, these toxic materials seep out into the environment, contaminating land, water and the air. In addition, devices are often dismantled in primitive conditions. Those who work at these sites suffer frequent bouts of illness,” Greenpeace said.
Moreover, with the use of recyclable and biodegradable polymers developed by Prof. Eugene Chen and post-doctoral fellow Miao Hong at CSU, the huge pile of e-waste could be reduced substantially, with the plastics being used again and the metals in computers, cellular telephones and tablets retrieved with less waste.
For his work on the completely recyclable and biodegradable plastic, Chen was recently bestowed the Presidential Green Chemistry Challenge award.
In their report to the November 23, 2015, issue of Nature Chemistry, Chen and Miao described the characteristics of the polyester that when simply reheated for an hour converts back to its original molecular building blocks and is, thus, ready for reuse.
Biodegradable plastics have been around for some time, Chen noted, and most of them are made from the biomaterial polylactic acid but they are not fully recyclable.
Chen and Miao worked on bio-renewable monomer that everyone else declared to be non-polymerizable, meaning that it could not form the long molecular chain structure that make up polymers.
Worse, the monomers had to be tied to each other to create a cohesive, solid material like plastic and the two worked on the long polymer chains that were stable and could not be broken down.
“More than 200 pounds of synthetic polymers are consumed per person each year – plastics probably the most in terms of production volume. And most of these polymers are not biorenewable,” Chen revealed.
“The big drive now is to produce biorenewable and biodegradable polymers or plastics. That is, however, only one part of the solution, as biodegradable polymers are not necessarily recyclable, in terms of feedstock recycling,” he noted.