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BIODEGRADABLE PLASTICS

Ever wondered what happens to the pile of plastic grocery bags sitting at your kitchen table or the bottle of water you are sipping totally drained with all the shopping you just did? Envision a day without utilizing anything made out of plastic. Even better, conjure up a list of your everyday necessities and examine for materials made out of plastic. Astonishing results, right?

To answer our opening question it would be totally naïve to presume that journey of a plastic product ends right after you dispose of it. Plastics are the most versatile, pliable, acceptable and adaptable substances known to mankind and have been corrupted in every possible manner. While the pros are countlessly abundant, we simply can’t disregard the ramifications of its profound exploitation. It is polluting, indestructible, non-biodegradable and toxic in incomprehensible ways. Finding alternatives to this situation leads us right to the concept of biodegradable plastics.

 

Need for Biodegradation

Biodegradation is nature’s recycling process where in a material is decomposed by the means of microorganisms or any other apt biological means. If something is considered biodegradable, it means that it can be broken down from its toxic complex form to simpler molecules by the action of bacteria or other biological entities.

Talking about various other methods of plastic waste treatment, incineration of non-biodegradable leads to a massive release of toxic gases (primarily Carbon dioxide) into the environment (which by the way is almost clogged up soaking already released harmful emissions on a daily basis.)

Disposing of plastics in landfill environments doesn’t do any good either. Plastics just keep sitting there for a considerably huge amount of time (decades or centuries even) before showing any remote signs of further degradation.

What are Biodegradable Plastics?

Adding detail to our understanding of biodegradation let us now familiarize ourselves with biodegradable plastics and if they are the right and effective alternative to their non-biodegradable counterparts.

As the name suggests Biodegradable Plastics are those plastics that can be decomposed (broken down) by the action of microorganisms such as bacteria and fungi under proper conditions. The extent of decomposition hinges on the class the biodegradable plastics belong to.

The usual non-biodegradable plastics are made up of long chain complex polymers of Ethylene, Propylene, Butadiene, Benzene etc. which makes them almost impervious to the degrading actions. While in the case of biodegradable plastics that are generally starch based consist of molecules that can be readily attacked by microbes and subsequently disintegrated into smaller molecules.

 

Classification

Biodegradable plastics can be broadly categorized into two types: Oxo-biodegradable Plastics and Hydro-biodegradable Plastics. Let us discuss these in details.

Oxo-biodegradable Plastics

Oxo-biodegradable plastics are still conceived out of fossil fuel by-products but do contain certain additives introduced into it, changing the expected behavior of the plastic leading to a significant increase in the degradation process and considerable reduction in plastic life span.

In this category of plastics decomposition begins with oxidation process and is carried forward by microbial action until the plastic is broken down to its structural unit and consumed by the microorganisms. While still in the manufacturing phase it is possible to decide the lifespan of the bio-degradable plastic by controlling the conditions under which it is prepared and the composition of the additives. The good part obviously is the little or almost no additional cost encountered in the production of the oxo-biodegradable plastic using this method. Basically it can be made using same tools and manpower utilised in the production of the conventional non-biodegradable plastic.

 

Hydro-biodegradable Plastics

Hydro-biodegradable plastics also more commonly known as “bioplastics” are basically starch based biodegradable plastics derived from renewable sources such as agricultural by-products. The decomposition of the bioplastics can occur either in aerobic or anaerobic environment. There is still a lot of fuss about considering bioplastics as “renewable”. Since they are made of crops itself, it implies them as a substantial user of fossil-fuel energy and emission of greenhouse gases adds to the implications.

There are different types of hydro-biodegradable plastics. Some most commonly used are:

  • Starch based plastics
  • Cellulose based plastics
  • Polylactic Acid (PLA)
  • Poly-3-hydroxybutyrate (PHB)
  • Polyhydroxyalkanoates (PHA)
  • Polyamide 11 (PA 11)
  • Polyhydroxyurethanes (PHU)

But there are certain issues pertaining to the manufacturing and utilization of hydro-biodegradable plastics as a bio-degradable alternative. Primary concern being their root source a major food crop. With the world dealing with major concerns of lack of food resources in various parts of the world, this alternative may not be the best suited to tackle the problem at hand. The cost of production is significantly higher than that of conventional plastics which makes it lose points in the economical aspect too.

Why bio-degradable plastics still lag behind?

Over last couple of decades our environment has been in a constant state of war with the growing needs of mankind and has already suffered a substantial amount of degradation. With this being said, is it not in our best interest to pursue this alternative of bio-degradable plastic over the conventional non-biodegradable ones? Let us take a look and analyze if it as feasible as it seems. There are a variety of factors to be considered before we arrive at any particular conclusion.

  • Not all bioplastics are biodegradable, unless provided with a specific set of conditions. The facilities that provide these conditions are still a handful in number.
  • The emission of Methane in the same amount as emitted during the degradation of conventional plastics is also a major concern.
  • Cost effectiveness is another lacking attribute adding to the low popularity of bio-degradable plastics. People aren’t willing to shell out 2-10 times more money for the bio-degradable plastics even if they care about the environment.
  • Reduce, Reuse and Recycle is still the more popular choice.

So even if we don’t accept bio-degradable plastics as the successful alternative to the traditional plastic, we can still play our role in protecting the environment. Reduce. Reuse. Recycle. Most importantly, stop littering!

 

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