While some countries are phasing out single-use plastic straws, their “greener” alternatives have some drawbacks of their own. Well, scientists have now developed bioplastic straws that are non-watery and biodegrade when discarded.
We have seen other experimental eco-friendly straws, some (such as those made of paper) that break when wet, while others (such as those made from sugar cane) require a complex manufacturing process. Non-disposable multi-purpose straws are certainly one option, but not everyone has such a straw whenever they have a drink on the go.
With these limitations in mind, scientists at South Korea’s Inha University turned to lignin, a type of organic polymer that makes up much of the supporting tissue of plants, including trees.
It is also a by-product of the pulp and paper industry and has previously been suggested for use in applications such as cheaper batteries, waste-derived carbon fiber and stronger concrete.
The researchers combined lignin with potato starch or plant-based polyvinyl alcohol (PVA) and added citric acid to the mixture. He then spread the slurry into a thin sheet, rolled the sheet into a cylinder to dry, and heated the cylinder in a vacuum to a temperature of 180ºC (356ºF).
Adapted from ACS Omega, 2023, DOI: 10.1021/acsomega.2c07797
The resulting bioplastic was self-sealed along the seams to form elongated tubes and cut into individual flexible straws. was also strong. However, the conventional straw was unchanged after he was exposed to the elements for two months while left outdoors, whereas the lignin straw was significantly biodegraded.
A paper on this study, led by Dickens Agamba, Doc Hoa Pham, and Jaehwan Kim, was recently published in the journal. ACS Omega.
Source: American Chemical Society
