Non-wet paper straws that can be completely degraded are available
The most commonly used coating material for paper straws is polyethylene or acrylic resin, and paper cups are also coated with the same material as paper straws. Numerous previous studies have shown that the polyethylene coating on discarded paper cups breaks down into microplastics. In addition, traditional paper straws will get wet after long-term contact with liquid, which is inconvenient to use. Polylactic acid straws and straw straws are alternatives to paper straws, but the former cannot decompose in the ocean; the latter, although easy to decompose, are difficult to produce on a large scale.
In the latest study, scientists at the Korea Institute of Chemical Technology have developed 100% biodegradable, environmentally friendly paper straws. They synthesized a biodegradable plastic, polybutylene succinate, by adding a small amount of cellulose nanocrystals to create a coating material. Since cellulose nanocrystals have the same main component as paper, the newly developed plastic adheres firmly to the paper surface. Because the coating material can evenly and firmly cover the surface of the straw, the straw is not easy to get wet, and the coating material is made of biodegradable plastic, which can also be completely decomposed.
The study found that the eco-friendly paper straws remained intact in both cold and hot beverages. When used to stir beverages like water, tea, milk, or in contact with liquids for a long time, the straw will not get wet. After soaking in cold water at 5°C for 1 minute, a traditional paper straw will bend severely when it weighs 25 grams. But under the same conditions, the new paper straws did not bend even if they weighed more than 50 grams.
The new straws also break down well in the ocean. The experiment found that ordinary plastic straws and polylactic acid straws were soaked in seawater for 120 days, and the total weight was only reduced by 5%. After being soaked in seawater for 60 days, the weight of the new straw was reduced by more than 50%, and it completely decomposed after 120 days.
