Monday 14 December 2020

Biomaterial bonanza: putting plastics out of a job

With the rapidly approaching midwinter (at least for the Northern Hemisphere) festival - and traditionally a time of gift-giving - wouldn't it be great to say that humanity can offer a present to the entire planet? The amount of plastic-based products manufactured every year is somewhere between three hundred and four hundred million tons, about fifty percent of which is single-use or disposable. 

Presumably if you've got any sort of interest whatsoever in the world around you (and how your children will get on) then you have been replacing disposable plastic items with reusable non-plastic, or at least biodegradable, alternatives. But are the companies producing the latter guilty of subtle greenwashing?

A friend recently told me that he had put some allegedly biodegradable plastic bags into his compost heap, only to retrieve them - albeit with some holes in - a year or so later. Bearing in mind there isn't an internationally-recognised set of characteristics for just what defines biodegradable, is it surprising that the wool (sorry, polyester) is being pulled over consumers' eyes?

A report last year summarised a three-year research programme at the UK's University of Plymouth, offering clear evidence that many types of allegedly biodegradable bags do not break down when buried in soil or underwater. Although the material did decay in open air, it was just into smaller pieces of plastic rather than degrading into simpler molecules. 

Recent studies by Tel Aviv University and the Goethe Universität in Frankfurt go even further in putting allegedly ecofriendly materials in a bad light. Both claim that not just biodegradable plastics but even those based on starch and cellulose contain numerous toxic chemicals. Such materials are used in food and drink packaging. So where do we go from here?

Last year I wrote a post about the potential of chitosan, a genuinely biodegradable material made from marine arthropod carapaces (i.e. shellfish discards) that can be produced in an eco-friendly process. 

There now appear to be several other materials that also have the possibility to replace traditional plastics. A group at the University Of Science And Technology Of China have developed a lightweight but durable material using mica and cellulose-derived nanofibre that has more than double the strength of high-performance petroleum-based plastics.

Another alternative to plastic that utilises surprising source material has been developed by a student at the University of Sussex in the UK. Lucy Hughes has used red algae to augment discarded fish scales and fish skin to produce a single-use translucent substance called MarinaTex. In addition to its use of material otherwise destined for landfill, MarinaTex - which biodegrades within six weeks - is the antithesis of conventional plastics in that the red algae component makes its production carbon positive! 

The bad news is that both materials are still at the research and development stage and there is no indication of when they would be ready for commercial mass-production. Crucially, there doesn't appear to be any news of large corporations buying the research for implementation; why is it that so many paradigm-shifting projects are having to be developed by crowd-funded start-ups rather than established multi-nationals? 

Surely there are enough ethical executives out there to pick up once the research has shown such potential? But as I've no doubt mentioned before, we are living in a world where the largest national economy - the United States of course - spends more each year on pet grooming products than on nuclear fusion research. Will future historians dub our era the Decades of Dubious Sanity?

Meanwhile, immense amounts of plastics are dumped in landfill and the oceans, polluting everything, including microplastics in the food we eat. Isn't it time these researchers are given the backing they need to convert smart ideas into ecosystem saviours? After all, no-one, no matter how wealthy, can opt out of the planetary biosphere!