The Future of Biopolymers

Imagine living in the ocean, with beautiful coral reefs of vibrant colors, fish of all sizes, the algae that seem to wave back at you, and mounds of underwater rocks. Then suddenly, you choke. A smooth, foreign material lodges itself in your throat. As you suffocate and struggle, your world fades to darkness. You’ve just experienced the final moments of a sea turtle, killed by plastic pollution.

We Need to Stop Killing Ourselves

Plastic is an artificial substance that can be shaped into many different forms. It is made of polymers, which are characterized as being made up of many repeating units. Every year, 20 million metric tons of plastic litter are estimated to end up in the environment. This number is projected to increase significantly by 2040 (IUCN, 2024). Plastic pollution is not a matter to be taken lightly. Once these polymers are exposed to the environment, they can take over 1000 years to completely decompose (EPA, 2024). Plastic pollution doesn’t just affect marine life—it affects us. Ocean waves and radiation from the sun break degrade plastic litter into microplastics. These microplastics contain toxic chemicals and float around in the environment, eventually being consumed by means of food, water, and air. These microscopic microplastics have large consequences, as they can end up in our bloodstream, livers, and kidneys, leading to lethal diseases such as cancer (Gold, 2023). While this problem is daunting, scientists are making progress on sustainable polymers—materials that could replace traditional plastic as a safer and biodegradable alternative.

Recent Innovations in Bio-based Polymers

Plastic itself was once a major breakthrough—revolutionary for preserving, protecting, and transporting goods (Babaremu et. al, 2023). Modern breakthroughs now lie in innovations of sustainable polymers that can replace traditional plastics. Biopolymers—also known as bio-based degradable polymers—are becoming increasingly popular alternatives to replace plastic. They contain substances such as acetal, silyl ether, and ketone, which are biodegradable. Unlike traditional plastics, which take centuries to decompose, these materials can break down more rapidly and safely in the environment (Babaremu et. al, 2023). 

Polysaccharides

Biopolymers can be made from renewable sources such as starch, cellulose, and chitin. Scientists are working on modifying starch, specifically thermoplastic starch, to be used as a biopolymer. This is because starch is mechanically weak and sensitive to moisture, which may make it less ideal than other biopolymers. Scientists have used corn starch and corn husk fiber to improve starches’ strength, making it a strong contender to replace plastic. Other possibilities include sugar palm starch and cellulose-based biofilms. These biopolymers are commonly used in food packaging as they are edible and safe to consume for humans (Babaremu et. al, 2023). One cool example? Cellulose has been used in packaging for confectionery, biscuits, tea, butter, and sealing films as it can act as a moisture barrier (Babaremu et. al, 2023). 

Polylactic acid (PLA)

Polylactic acid (PLA) is another popular alternative being explored to replace plastic and be used as a base in biocomposites. It is biodegradable and made from renewable materials such as potato starch, wheat, and rice bran corn (Samir et. al, 2022). What makes PLA stand out is its versatility—the material has good mechanical and thermal properties that rival petroleum-based plastics. Simultaneously, due to its biodegradability, PLA has good availability, eco-friendliness, and antibacterial properties. PLA is now being used in 3D and even 4D printing, an advanced version of 3D printing where printed objects can change their shape or properties due to to external stimuli like heat, light, or water that vary over time. This is thanks to the PLA’s shape memory effect, which allows it to change shape when exposed to heat (Trivedi et. al, 2023). 

Further studies needed

Currently, many biopolymers are mixed with harmful chemicals during production. The resulting plastics may have different characteristics and properties from the biopolymers used to produce them. For instance, the plastic may have weaker mechanical properties than the biopolymer used to manufacture it. Scientists need to further study how biopolymers react with other food items and chemicals, as well as develop a better understanding of their mechanical, thermal, and chemical properties (Babaremu et. al, 2023).

Product shelf life

Manufacturers struggle to find durable bio-sourced packaging without compromising their product’s shelf life. This is because biopolymers are usually thermal or hydro-degradable (Babaremu et. al, 2023), meaningthey are easily susceptible to environmental factors such as heat and moisture. Overall, biopolymers break down easily when exposed to high temperatures or moisture over time, which can discourage their function as a packaging material.

Human behaviour

Here’s an astonishing fact: most people cannot differentiate between different types of plastic! A handful of people believe that all bioplastics are biodegradable, but that is not always the case (Babaremu et. al, 2023). Bioplastics made from resources such as bio-polyethylene and bio-polypropylene cannot break down naturally. A common misconception is that biodegradable plastics can be recycled alongside other plastics, when in fact, they cannot. Due to this misconception, many put biodegradable plastics into the recycling bin instead of the home compost bin. Some may even say that biodegradable plastics are not as convenient and practical. This lack of understanding, coupled with the lack of conscious recycling, is among the many challenges that we must overcome to promote the use of biopolymer packaging (Babaremu et. al, 2023).

Future Outlook

Biopolymers face many setbacks as they are only in their foundation phase. Compounding this lack of credibility is that each biopolymer type has different disadvantages. Biopolymers lack in areas such as mechanical strength and are susceptible to environmental factors such as temperature and moisture. Further innovations could be studied and looked into to improve these aspects (Babaremu et. al, 2023). Overall, biopolymers may just be the key to a cleaner, safer future — if we’re willing to invest in their promise.

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Written by Tham Jia Huey

References

1. Babaremu, K., Oladijo, O. P. & Akinlabi, E. (2023). Biopolymers: A suitable replacement for plastics in product packaging.  Advanced Industrial and Engineering Polymer Research, 6(4), 333-340. https://www.sciencedirect.com/science/article/pii/S2542504823000088

2. Gold, E. (n.d.). What you need to know about the impact of plastics on human health. EarthDay.org. https://www.earthday.org/what-you-need-to-know-about-the-impact-of-plastics-on-human-health/

3. International Union for Conservation of Nature. (n.d.). Plastic pollution. https://iucn.org/resources/issues-brief/plastic-pollution

4. Samir, A., Ashour, F.H., Hakim, A.A.A. et al. (2022) Recent advances in biodegradable polymers for sustainable applications. npj Mater Degrad 6, 68. https://doi.org/10.1038/s41529-022-00277-7

5. Science History Institute. (n.d.). The science of plastics. https://www.sciencehistory.org/education/classroom-activities/role-playing-games/case-of-plastics/science-of-plastics/

6. Trivedi, A. K., Gupta, M. K. & Singh, H. (2023). PLA-based biocomposites for sustainable products: A review. Advanced Industrial and Engineering Polymer Research, 6(4), 382-395. https://www.sciencedirect.com/science/article/pii/S2542504823000167

7. U.S. Environmental Protection Agency. (n.d.). Impacts of plastic pollution. https://www.epa.gov/plastics/impacts-plastic-pollution