New Way of Degrading Plastic!

Sanjana Mupparaju

It is largely known that plastic is very harmful to the environment. This is because it is largely nonbiodegradable and can pile up in our ecosystems for thousands of years. However, plastic is ubiquitous in human life, used in everything from candy wrappers to straws. When thrown away, it ends up in spaces like the ocean, where marine life gets suffocated and entangled in it. The risk to biodiversity and ecosystem health that plastic pollution is creating has led to scientists trying to design materials with plastic-like properties, but that also is biodegradable. Currently, a common replacement material is called polylactide acid or PLA. Even though PLA degrades faster than plastic, it still takes a long time to degrade and only with specific conditions. In seawater, it can take up to three years; far better than the thousands of years it takes plastic, but still long enough to be harmful. Essentially, it needs improvement.

So what can degrade in seawater? RNA, through a process called transesterification, is easily broken apart by water. With knowledge of that process, scientists wondered if they could incorporate properties of RNA involved with transesterification into PLA to make it more biodegradable in sea water. To do this, they added transesterification sites like the ones found in RNA onto PLA. They created different samples of PLA, each one with a different number of sites and released each sample into some artificial seawater. To understand the amount of degradation, they measured the amount of lactic acid produced (the degradation product of PLA) and the change in weight of each sample. They found that the sample that had the most transesterification sites degraded completely and in two weeks. As the number of transesterification sites decrease, the speed of degradation decreased. This research shows promising hope for the future regarding plastic substitutes.