Chinese scientists have succeeded in producing a tough, biodegradable plastic made from bamboo that is as strong and durable as conventional plastics and is suitable for applications such as household appliances and car interiors. The key difference is that, unlike conventional plastics, it is easily recyclable and also decomposes in the soil.
In recent years, bioplastics, which are produced from organic sources, have attracted a lot of attention. However, their share of the total of more than 400 million tons of plastic produced worldwide is still less than half a percent. The main reason for this is their mechanical weakness compared to petroleum-based plastics and their incompatibility with conventional industrial production methods.
Bamboo plastic rivals many widely used plastics A new innovation developed by a team led by David Zhao at Shenyang University of Chemical Technology in China could be the answer to the environmental challenges posed by petroleum-based plastics. The team has created a plastic based on cellulose extracted from bamboo that is as strong and durable as, or even better than, many widely used plastics.
Bamboo is a highly renewable and sustainable resource because it grows quickly, Zhao explains, and could be a good alternative to traditional wood, but its current applications are still largely limited to traditional woven products.
The process for making the new biodegradable plastic involves treating bamboo with a solution of zinc chloride and a simple acid, which breaks the strong chemical bonds in its cellulose structure, yielding a solution of smaller cellulose molecules. The next step is to add ethanol, which causes the molecules to rearrange themselves into a hard, plastic material.
The strength of the resulting plastic is comparable to that of common engineering plastics used in cars, household appliances and construction, says Andrew Dow of the University of Birmingham in the UK. However, he stresses that the material’s extreme hardness limits its potential applications.
“This plastic is not intended to replace materials such as polyethylene or polypropylene in the packaging industry, but in the engineering plastics sector it could help reduce the pressure on oil resources,” Dow says.
Although bamboo plastic costs more to produce than petroleum-based materials, the results show that it can be fully recycled and retains about 90 percent of its original strength, a significant economic advantage.
It is also reported to decompose in soil within 50 days, although like many other biodegradable plastics, this claim requires further investigation and more rigorous scientific verification.
