Conventional paper straws are inconvenient to use. With prolonged contact with a liquid, they become soggy. When these straws are used to drink carbonated drinks, many air bubbles can form due to their surface properties.
Currently, polylactic acid (PLA) straws and rice straws are available in the market as an alternative to paper straws. However, PLA straws, also known as corn plastic straws, do not decompose well in the ocean.
The joint research team of Dr. Oh Dongyeop and Dr. Kwak Hojung of KRICT and Professor Park Jeyoung of Sogang University have developed eco-friendly paper straws that are 100% biodegradable, outperform conventional paper straws and are easy to mass-produce. . These straws can quickly become soggy and biodegradable.
According to scientists, these straws are expected to be introduced in response to regulations on plastic straws in restaurants and cafes.
By combining a small number of cellulose nanocrystals with a known biodegradable plastic, polybutylene succinate (PBS)*, the research team’s method was used to develop a coating material. The biodegradable plastic can adhere firmly to the paper surface during the coating process thanks to the additional cellulose nanocrystals, which are made from the same substance as the main paper component.
The research team found that these eco-friendly paper straws maintain their physical integrity in hot and cold drinks. The scientists also found that the straws did not get soggy when used to stir a variety of liquids, including water, tea, fizzy drinks, milk and other liquids containing lipids. The soggyness of the paper straws during preparation and the traditional paper straws were compared.
The research team performed a decomposition test in a marine environment by submerging the straw samples at a depth of 1.5 to 2 m on the coast near Pohang, South Korea. They lost more than 50% of their weight after 60 days and completely decomposed after 120 days.
Principal investigator Dr. Oh Dongyeop said: “This technology is just a small step in the direction we need to take in this era of plastic. Changing the plastic straw we often use to a paper straw will not have an immediate impact on our environment, but the difference will be significant over time. If we gradually move from using convenient disposable plastic products to various eco-friendly products, our future environment will be much safer than what we worry about now.”
- Hojung Kwak, Hyeri Kim, et al. Biodegradable, water-resistant, anti-fizz, polyester nanocellulose composite paper straws. Advanced science. DOI: 10.1002/advs.202205554