Environmental Question #13 [Bioplastics Deep Dive]

Courtesy of Reddit user u/That_Boysenberry4501

Q:  I am very interested in algae bioplastic and I've been experimenting with my own for art. What do you think of bioplastics (algae and other) current potential to replace the worlds plastic? Is it mostly political/laws that are needed to even get plastic replacements and restrictions going? Why are we not more urgently finding/implementing plastic replacements?  

A: Bioplastics are actually my main field of expertise and I hold a few patents on new bioplastics, so as a disclaimer I am very knowledgeable on this topic, but also very biased. I am very much in favor of bioplastics.

The short answer to your question is that bioplastics have a lot of potential, and I am confident they will safely replace a huge portion of plastic products, but they shouldn't replace all plastic, because most of the products we make out of plastic now shouldn't be made of plastic to begin with.

As an example, the largest plastic polluter in the world right now is the Coca-Cola company, and they have only been using plastic bottles since 1978. Before then Coke used to come in glass bottles that people would return to the grocery store, then Coca-Cola would pick up the bottles, wash them, then use them again. Nothing about the world has changed since 1978 that would prevent Coca-Cola from bringing the old system back, other than the fact that it is financially cheaper to pollute the ocean with plastic bottles than it is to make and wash reusable bottles.

This example applies to a wide range of industries. There are definitely some applications where plastic is the best tool for the job, and I'm confident bioplastics will step in to fill many of those roles, but the bigger solution for plastic pollution worldwide is to stop doing the metaphorical equivalent of trying to drive in a nail with a screwdriver.

I'll give another example to illustrate my point. A company called Solvay recently invented a new type of biodegradable nylon called Amni Soul Eco. This nylon is indistinguishable from regular nylon and it carries the major benefit of biodegrading naturally into nontoxic products after about 5 years in the environment. They're currently marketing this material for swimsuits, and I think that's awesome! Only certain fabrics work for swimsuits so they don't become too waterlogged, and prior to nylon's invention silk was the swimsuit fabric of choice. Silk is very difficult and expensive to source, so using a biodegradable plastic to meet this specific need is amazing! However, beyond swimsuits plastic fabric is used for lots of different types of clothes in the form of polyester. Polyester is used primarily as a substitute for cotton or wool, and I don't think we should pour resources into inventing a polyester replacement when we could just go back to using cotton and wool instead.

Synthetic plastic has only existed for about 100 years, and it has only been widely in use for about 50 years, which in the grand scheme of things is not a very long time at all. Today the best plastic replacement in most cases is not bioplastics, it's going back to the old way of making things. The only thing standing in the way of returning to those practices and building on them is the fact that today it is cheaper to pollute than it is not to pollute. That's why many activists and policy-makers advocate for making manufacturers pay for the disposal cost of their products, that way the ecological cost of pollution becomes a financial cost that those companies need to factor in.

On the topic of algae plastic and bioplastic more specifically though, the technology will continue to improve, but adoption will continue to be an uphill battle for some time. When designing biodegradable materials you always need to consider what your biodegradation trigger will be, which is the stimulus that causes the material to start biodegrading. This also creates some limitations for what that material is useful for. For example, compost heaps get pretty hot, so you could design a material that begins biodegrading once it reaches a certain temperature. That would work great for things like garbage bags, which rarely get hot, but it would be terrible for disposable coffee cups, which are hot all the time. The most common triggers that are used are temperature, water exposure, sunlight exposure, and exposure to bacteria. I'm sure you can imagine how hard it is to choose a trigger that a product will not be exposed to in its day-to-day use that it will be exposed to when it is thrown away. This puzzle can be solved of course, but it requires tailoring the material choice very specifically to the product being designed. However, right now the same type of conventional non-biodegradable plastic is used to make garbage bags, water bottles, and sweatshirts. So convincing an industry like the plastic industry that has gotten very accustomed to one size fits all solutions that every product needs a different material and needs to be handled in a different way is a consistent challenge for adoption of bioplastics. My colleagues and I are determined to keep pushing this boulder up the hill by solving bioplastic puzzles one by one, and I think we would benefit the most by focusing our efforts on applications that absolutely need plastic, rather than inventing new solutions to problems that were already solved 50 years ago. 

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