New Materials for the Environment - Bioplastics

What is bioplastic?

 Bioplastics are plastics or polymers and are considered to be an alternative to “regular” plastics. Bioplastics are different to “regular” plastics when it comes to “sourcing” and “end-of-life options”. Carbon sourcing means that You need carbon (C) atoms to make plastics. Historically, “regular” plastics have been made with carbon from “fossil” origin (crude oil, gas). When bioplastics are an alternative to this type of “fossil carbon” plastics, they are referred to as bio-based, bio-sourced, bio-equivalent or bio-similar plastics. End-of-life option is the answer of  "What happens to the plastics after it has fulfilled its use?" In other words, "what happens to the plastic waste?" The most preferred or traditional end-of-life option for plastics is “recycling”. When bioplastics are an alternative to this type of “recyclable” plastics, they are referred to as biodegradable, compostable and bio-recyclable plastics. In short, bioplastic refers to plastic made from renewable raw materials, and it is a concept that contrasts with plastic made from fossil raw material-based powders such as oil and natural gas.

Example of bioplastic

 Bioplastics are largely divided into Bio-degradable Plastics, Oxo-Biodegradable Plastics and Bio-Based Plastics. Bio-degradable plastics refer to plastics containing more than 70% of biomass derived from plants such as corn. The final biodegradation period is within 180 days. Although there are problems such as price competitiveness and the possibility of decomposition during the distribution period, it is spreading mainly to disposable products. Oxo-biodegradable plastics refer to polymers that are first oxidized and then biodegraded in heat and sunlight. The final biodegradation period is within 180 days, and is mainly used in food packaging materials, industrial products, and agricultural and horticultural fields with a product shelf life of more than one year. Finally, bio-based plastics are plastics containing more than a certain amount of biomass, and they are bioplastics that focus on reducing carbon dioxide rather than biodegradation period.

 There are various types of bioplastics. For example, polylactic acid(PLA), Polyhydroxyalkanoates (PHA) and polycaprolactone(PLC). Among them PLA is currently the most used bioplastic. It is made from renewable resources such as cornstarch, sugarcane, and cassava. It is commonly used in food packaging and disposable tableware, as well as in 3D printing. PLA is biodegradable in commercial composting facilities and breaks down into carbon dioxide, water, and organic matter. PHA is a group of biopolymers produced by microorganisms such as bacteria and algae. It is used in various applications such as packaging materials, disposable diapers, and medical implants.  PHA is biodegradable in both industrial and home composting facilities, as well as in soil and water. And PCL is a bio-based plastic made from petrochemicals and is commonly used in 3D printing, drug delivery, and wound healing applications. It is biodegradable in industrial composting facilities and can also break down in soil and water.

Only good points?

 Looking at the above alone, you may think that bioplastic is the perfect material. But that’s exactly wrong. Even biodegradable plastics decompose well under certain conditions, but out of those conditions, they often become a material that is no different from regular plastics. The best example of this is PLA. Many people used this product because they thought it was eco-friendly. However, in fact, PLA decomposes into lactic acid only at high temperatures. Experimental results have shown that it didn’t decompose at all when it was placed at low temperatures in seawater for 14 months. Dr. Dimitri Dehane, a marine biologist, said: "Bioplastic such as PLA is recognized as biodegradable in the environment because of its prefix bio, but it is different from the real thing." Through this, he emphasized that the PLA is not as eco-friendly as people thought.

The future of bioplastic

 Still, bioplastic has many problems and disadvantages to be supplemented, I believe that one day there will be eco-friendly materials that can completely replace regular plastic.