By making alterations to the plastic manufacturing process, scientists hope to produce forms of the ubiquitous material that can break down far more safely and quickly in the environment than current versions do. Researchers in China have now demonstrated a new example of this that degrades in just a week when exposed to sunlight and oxygen, which they believe could make for electronics that are easier to dispose of at the end of their lives.
The new material came about when study author Liang Luo from China's Huazhong University of Science and Technology was working on an advanced type of chemical sensor, as reported by PNAS. The materials scientist was developing a novel polymer film that changed color in response to pH levels. This process was driven by the material's unique molecular structure, with the chains of monomers giving the film its deep red color, and taking it away when these bonds were broken.
Through his team's experiments, Luo found that the deep red color of the film quickly faded away and the material broke apart after several days in the sunlight. Breaking apart these bonds is a common objective in research efforts to better recycle plastics, and in doing so Luo may have inadvertently conjured up a promising, environmentally friendly version of the material.
The molecular makeup of the plastic means it wouldn't be suited for use in soda bottles or shopping bags, as it is only stable as a functional material in the dark and without oxygen. But exposed to sunlight and air, it disintegrates rapidly and completely decomposes within a week, leaving no environmentally damaging microplastic fragments behind. A byproduct of the process is naturally occurring succinic acid, however, which could potentially be upcycled for commercial use in pharmaceuticals or food.
Where the plastic could find use, however, is in flexible electronics or smartphones, where it would be isolated from air and light during its service life. Luo imagines the material could last for years when used in this way, and then make these types of devices easier to dispose of after use. He plans to continue to explore the possibilities around these types of degradable plastics, but notes that commercialization is still years away.
The research was published in the Journal of the American Chemical Society.
Source: PNAS
