Biodegradable plastic made from bamboo is strong and easy to recycle

Hard plastic made from bamboo is as strong and durable as conventional plastics for uses such as household appliances and car interiors, but it is also recyclable and biodegrades easily in soil.

Plastics derived from biological materials, or bioplastics, are increasingly popular, but they still only represent about 0.5% of the more than 400 million tons of plastic produced each year. This is partly because bioplastics do not have the mechanical strength of many petroleum-based plastics, nor can they be easily used in common manufacturing processes.

Now, Dawei Zhao of Shenyang University of Chemical Technology in China and colleagues have developed a way to produce plastic from bamboo-derived cellulose, which can replicate or surpass the properties of many widely used plastics.

“The rapid growth of bamboo makes it a highly renewable resource, providing a sustainable alternative to traditional wood sources, but its current applications are still largely limited to more traditional woven products,” says Zhao.

Zhao and his team first treated the bamboo by adding zinc chloride and a simple acid, which breaks the strong chemical bonds and produces a soup of smaller cellulose molecules. They then added ethanol, which allowed the cellulose molecules to rearrange into a strong, solidified plastic.

The plastic’s strength is comparable to that of commonly used engineering plastics – tough plastics used in vehicles, appliances and construction, says Andrew Dove of the University of Birmingham, UK, who was not involved in the study.

However, its rigidity also means that its potential uses are not the most widespread. “This is not something that is going to challenge the use of the main plastics that we use in packaging, like polyethylene and polypropylene,” Dove says. “But even though it targets a narrower set of engineering plastics, it could still help alleviate some of the incumbent’s supply concerns. [plastics] in this area. »

Although it’s not as cheap as some of the more commonly used plastics, Zhao and his team found that it can be fully recycled while retaining 90 percent of its original strength, which could make it more economically attractive. They also report that it is biodegradable within 50 days, although this claim has not held up to the scrutiny of other biodegradable plastics.