BIODEGRADABLE PLASTICS – WHY THEY MATTER


I remember traveling to work sometime ago and encountering a ‘sea’ of plastic papers around a certain town centre.

Now this region was inhabited by cattle herders and I couldn’t imagine the pain they went through when their cattle chewed onto these plastics.

You see normally, plastics don’t degrade over our lifetime.

Infact some are so persistent they stay longer than a generation or two.

But the challenge with plastics is more than just being long term pollutants.

PLASTICIZERS

Plastics are made up of the joining together of small molecules called monomers.

Since these monomers end up forming a very rigid structure, some substances are added to make them flexible.

These substances are called plasticizers. 

The ones that draw most attention are – phthalates, some heavy metals etc.

Don’t worry about the chemical terminologies here.

What’s important is that these substances could leach out from plastics into our environment causing pollution – this could happen especially when plastics are exposed to heat.

But that’s not all.

If perchance we absorb them through food, water or the air we breathe, they are bound to cause health complications in the long run.

But plasticizers aren’t the only source of concern in this regard.

MICROPLASTICS

These are small fragments produced from breakup of plastic stuff over time.

You see, since plastic doesn’t degrade,  it still could disintegrate into mini plastics which could find their way into our water,  air or food.

Microplastics have started gaining prominence in the recent past because of increased awareness about plastic pollution.

However, more studies are being done to determine their health effects – which don’t look good at all.

That being said, why is biodegradable material being touted as a good replacement for durable plastics?

BIODEGRADABILITY

In the same way plastics resist degradation, biodegradable stuff breaks down easily in the environment.

Picture this example…

When a leaf falls from a tree, it’s only matter of time before it disappears before our very own eyes.

But in real sense, the leaf hasn’t disappeared.

It’s just broken down to it’s harmless but beneficial primary constituents – gases, humus etc.

In the same way, biodegradable substances break up into their primary constituent substances which do not harm the environment. 

And nature has availed to us many options to choose from when it comes to biodegradable material useful for packaging.

CELLULOSE

This is the most abundant naturally occurring polymer material on earth.

– A polymer is a substance made up of many monomer molecules joined to each other just in the same way we make plastics.

But the difference between cellulose and plastic is that it naturally degrades into useful humus – fertile carbon matter – in the soil.

Cellulose could be extracted from several sources including trees, grass, hyacinth, weeds etc.

Having a combined advantage of toughness and durability – without damage to the environment  – cellulose makes a good packaging material.

And several start ups have banked on its extraction from wastes such as hyacinths.

Take for instance Takawiri Craft Entreprises run by Mr Michael Omondi.

This startup extracts fibre from water hyacinth to make packaging material used in bookshops, supermarkets etc.

Being the most abundant polymer, there are no shortage of opportunities to extract and use cellulose.

For example, it could be extracted from grass clippings, weeds etc.

But cellulose not only helps us make biodegradable packaging material, it also inspires us to exploit other possibilities around us.

MANGO MATERIALS

Mango materials is a start up using methane from waste to make biodegradable plastics.

It feeds special bacteria with methane which they use to convert to biodegradable plastics which they sell to businesses.

These plastics break down easily releasing methane which could be reused to make more plastics.

This – and other such companies – bank on bacteria which are nature’s engines for production of recyclable products.

Perhaps this is an opportunity for scientists and engineers to plug into for further research and innovation.

IN CONCLUSION

Biodegradable plastics are the way to go in this age of plastic pollution.

It will go a long way in reducing the challenges plasticizers and microplastics bring to our world.

So where are the innovators, the chemists, physicists, biologists, engineers, entrepreneurs willing to venture into this space?

Photo credit: George Becker via Pexels

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