(Nanowerk News) Plastic waste is a big problem for the environment, especially small plastics such as tongs of bread which are difficult to recycle or dispose of into the environment and can have a negative impact on living things. Various solutions have been suggested, including the use of biodegradable polymers for single-use applications and implementing plastic bans in several countries.
Biodegradable polymers include a wide range of options, such as fully biobased polylactic acid (PLA), partially biobased polybutylene succinate (PBS), fully synthetic polybutylene adipate terephthalate (PBAT), as well as natural polymers such as starch, polyhydroxyalkanoate (PHA), and polyhydroxybutyrate. (PHB).
However, it is very important to recognize that not all biodegradable polymers have the same characteristics, and it is very important to understand the specific properties and limitations associated with each type. For example, widely used biodegradable polymers such as PLA, PBAT, and PBS do not readily biodegrade under natural environmental conditions, requiring specific conditions such as controlled humidity and temperature typically found in industrial composting facilities. Therefore, it remains important to ensure the proper disposal and collection of these biodegradable materials at the facility to ensure their thorough degradation.
In contrast, starch-based, PHA and PHB-based materials are fully biodegradable in natural environments, presenting a potentially suitable option for certain applications where easy collection and recycling prove challenging or uneconomical, especially for small and light items or products. These materials have the ability to decompose completely without the need for special industrial composting facilities, offering a more practical and environmentally friendly solution for certain types of waste.
To overcome this problem by using starch-based ingredients, the team used starch from pineapple stems, a substance found in plants, as the main ingredient. The team added glycerol and calcium carbonate to make the material malleable and strong. By changing the amounts of these ingredients, the team created samples with different strengths and properties.
The resulting material can hold water and does not absorb as much water as other similar materials. When the team buried it in the ground, it literally fell to pieces in just two weeks. The team even made a trial version of a bread clip using this material, and it worked great at sealing bags.
This study shows that using pineapple stem starch can be a good and environmentally friendly option instead of using plastics made from petroleum or other plant materials. It is a step towards a more sustainable way of making small plastic products and promoting a circular economy.
A paper based on the study appears online in the journal Polymer (“Towards a Circular Bioeconomy: Development of Pineapple Stem Starch Composites as a Substitute for Plastic Sheets for Disposable Applications”).