Plastic Bags, Soluble in Water?

Published on 2 November 2020

It is shocking that over 4 billion plastic bags are disposed every year in Hong Kong. Plastic bags are notoriously difficult to decompose naturally, and causing many environmental problems. However, it is hard to give up using plastic bags in our daily lives, therefore reducing the use of plastic bags or reusing them is the utmost thing to do, followed by choosing alternative products with less environmental impact. Recently, plastic bags made of polyvinyl alcohol and starch can be found on the market.

Since polyvinyl alcohol is a water-soluble polymer, these plastic bags can be dissolved in hot water and degraded to carbon dioxide and water by microorganisms. There are many products made of polyvinyl alcohol, such as the outer film of the widely available laundry detergent pods. The film dissolves in water and disappears during the laundry process.

In the video, you may observe the difference between conventional plastic bags and polyvinyl alcohol plastic bags in hot water.

Moreover, the clear liquid glue used for crafting is a water solution of polyvinyl alcohol. You can try pouring some liquid glue on a flat surface and let it dry, and see if the texture of the dried film is similar to that of a plastic bag.

Clear liquid glue made of polyvinyl alcohol and its dried film.

Even though polyvinyl alcohol plastic bags might not be the perfect substitute to conventional plastic bags, it is always good to be more informed about these substitutes that we can make a greener choice in our daily lives. But no matter which plastic bag you choose, consider to reduce and reuse them for saving the environment.