By Dr. Andrew H. Dent
Our concerns over single-use plastics have existed for many years, with the development of recyclable and renewably-sourced plastics providing the main thrust against this environmental challenge. But in the last two years, we have a greater understanding of our microplastics problem, and there are clear examples of the sheer extent of polymer waste entering our oceans.
We have to rethink how we approach our reliance on plastics.
Almost all bio-based and recyclable plastics are great when they follow an ideal path to a recycling or industrial composting facility, but fail when they enter our waterways and oceans. Even organizations as forward-thinking as the European Bioplastics non-profit consortium has had to put out disclaimers about their materials, stating that they never claimed marine degradability and that bioplastics work well in strict disposal scenarios.
As consumers clamor for better solutions, the stark truth is that there are few alternatives to our existing petrol and bio-based plastics that will quickly and effectively degrade everywhere and not cause problems to our increasingly fragile ecosystem, whether it’s through composting or even in our oceans.
We can always go back to using glass and metals, and while they don’t degrade, they pose no significant challenge to ocean life. But this isn’t a solution, especially when lightweighting overall CO2 expenditure and flexibility in some packaging still remain components for a more sustainable future. Paper and pulp are great alternatives, but great care still needs to be undertaken with the types of protective, decorative or barrier coatings and binders that are used. This would also be a step back in some cases, as many consumers prefer to see the product that’s inside the packaging.
So what about bioplastics? Unfortunately, none of the current “beverage bottle” plastics that use some or all renewable raw materials will be suitable. PLA, the transparent moldable plastic that uses corn sugar from Natureworks, works well as a lower CO2 and non-petroleum solution, but is only industrial compostable, nor does it break down in seawater. Bio-PE from Braskem that uses sugar cane can give equivalent performance to that of petroleum-based polyethylene for shampoo bottles, molded containers and tubes are not intended to biodegrade quickly in any environment, but to be recycled in the same bin as HDPE (or plastic #2 for recycling purposes).
Similarly, Bio-PET produced by Virent and others from plant-based materials should go in the plastic#1 PETE recycling stream with the standard polyester and are also not intended for any biodegradation.
Currently, one of only two classes of bioplastics is considered marine degradable— the PHAs (Polyhydroxyalkanoates) from suppliers such as Full Cycle Bioplastics which, to date, have been used sparingly as a packaging source. There have been some forays into more substantially molded products with the material used to produce trays, cups and other food service items, but nothing that has done well commercially yet.
Additionally, transparent cellulosic packaging films and molded sheets like Natureflex from Futamura offer a potential solution, as they are compostable and, according to them, marine degradable.
The water-soluble starches from renewable raw materials used for foam packing peanuts and blocks from suppliers such as Sealed Air will break down in seawater as well as regular water. There are also some petroleum sources that offer the ability to create packaging that can degrade in our oceans, but these include those that are already water soluble, such as the films used to package tide pods and other detergents made from PVOH by producers like Aicello and Monosol.
Some new packaging materials like mycelium fungi from Ecovative will break down in our oceans, but currently, there are limited format options and are only used as polystyrene foam alternatives.
Algae is a component for low CO2 and renewably-sourced plastics from companies like Algix, but they can’t break down efficiently in seawater, and they weren’t designed to either. Algopack, a French company is developing polymer materials made entirely from seaweed. This type of granule, also called AlgoPack, is bio-compostable and biodegrades within 12 weeks in the soil and 5 hours in water. Its permeability can even be adapted according to a product’s lifecycle as well.
There are other materials with potential, including polycaprolactones that are used as bioabsorbable materials in medicine, like suture-controlled drug release, as well as some cellulose foams such as Sugi that could be tested for potential oceanic degradation, but haven’t been considered for commercial use in packaging applications.
In our attempts to move toward reducing ocean waste through the reduction of single-use plastics, there are options, but as with all disruptive innovations, each requires some level of compromise in terms of performance or cost. However, with clever and considered design for packaging using the unique properties of the material itself, we can make the next generation of packaging more respectful and accommodating to our environment.
Also, it makes for a better feel-good story when we decide what to purchase at the store.
Dr. Andrew H. Dent
Dr. Andrew Dent is Executive Vice President of Research at Material ConneXion, and Chief Material Scientist at SANDOW. He plays a key role in the expansion of Material ConneXion’s technical knowledge base. His research directs the implementation of consulting projects and the selection of innovative, sustainable and advanced materials to Material ConneXion’s library, which currently houses over 8,000 material samples.
Dr. Dent received his Ph.D. in materials science from the University of Cambridge in England. Prior to joining Material ConneXion, Dr. Dent held a number of research positions both in industry and academia. At Rolls Royce PLC, Dr. Dent specialized in turbine blades for the present generation of jet engines. He has completed postdoctoral research at Cambridge University and at the Center for Thermal Spray Research, SUNY, Stony Brook, NY. Other research projects, during this period, included work for the US Navy, DARPA, NASA, and the British Ministry of Defense.
Since joining Material Connexion, Dr. Dent has helped hundreds of clients—from Whirlpool and Adidas to BMW and Procter & Gamble—develop or improve their products through the use of innovative materials. A leading expert on sustainable materials, his insight has played an important part in creating a new generation of more sustainable products.
He is a frequent speaker on sustainable and innovative material strategies, having given two TED talks at TEDx Grand Rapids and TEDNYC, and is the co-author of the Material Innovation book series. Dr. Dent has also contributed to numerous publications on the subject of material science, including Business Week, Fast Company and the Financial Times.
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