Are Bioplastics really Bio?
 
 As plastic disposables start getting banned the world over, a new range of materials called Bioplastics are now emerging. Made with 'natural' materials such as cornstarch, tapioca, seaweed these seem to offer a promise to solve the problems created by petro based plastics. But how far is this true?
         The International Union of Pure and Applied Chemistry (IUPAC) cautions that the term 'Bioplastic' is a misnomer as it gives the impression that all bioplastics are environmentally friendly. Are they not?

Read more to understand what bioplastics actually are.
What are BioPlastics made of?
   Bioplastics are plastics derived from renewable biomass sources, such as vegetable fats and oils, corn starch, straw, woodchips, food waste, etc. The word 'bio' does not imply that these bio plastics are biodegradable nor that they biodegrade more easily than ordinary plastic.

          Yet, many are of the opinion that bioplastics could possibly be the answer to the plastic problem. Bio plastics are bio based polymers - as opposed to petro based polymers. As per the IUPAC , a biobased polymer similar to a petrobased one, is not necessarily superior in terms of environmental performance and cannot be judged as such, unless a lifecycle assessment is done.
Types of BioPlastics
STARCH BASED BIOPLASTICS   
Source: dailytelescope.com
Nearly half of the bioplastics currently being made in the world come from starch. Corn starch or rice are some of the sources of the starch which can also be combined with biodegradable polyesters to enhance its properties. Pure starch can absorb moisture and is used in medical products. Thermoplastic starches are more water resistant and are applied industrially.
CELLULOSE BASED BIOPLASTICS
Source: Direct Transformation of Edible Vegetable Waste into Bioplastics
Cellulose comes from plant materials and can result in a material that has plasticity but is more water resistant than starch. Agricultural wastes are a good source of cellulose for making bioplastics.
PROTEIN BASED BIOPLASTICS
Source: https://www.researchitaly.it
Proteins coming from both animal and plant sources can be converted into bioplastics. Wheat gluten, casein are examples of plant proteins as well as soy based protein. Milk is also being used to create bioplastics.
BIOPLASTICS FROM MICROORGANISMS
Source: https://labiotech.eu
Bacterial fermentation of sugar and microbial action also can create certain polyesters that are used in bioplastics. Polylactic acid is a transparent plastic produced from corn or dextrose.
PLA- Most common bioplastic in use today. PLA (polyactic acid) is typically made from the sugars in corn starch, cassava or sugarcane. It is biodegradable, carbon-neutral and edible. Corn kernels are immersed in sulfur dioxide and hot water, where its components break down into starch, protein, and fiber. The kernels are then ground and the corn oil is separated from the starch. The starch is comprised of long chains of carbon molecules, similar to the carbon chains in plastic from fossil fuels.  PLA can look and behave like polyethylene, polystyrene or polypropylene.
 
PHA- PHA (polyhydroxyalkanoate) is made by microorganisms, sometimes genetically engineered, that produce plastic from organic materials. Manufacturers harvest the microbe-made PHA, which has a chemical structure similar to that of traditional plastics. PHA is often used for medical applications such as sutures, slings, bone plates and skin substitutes; it is also used for single-use food packaging.
AND MORE...Bioplastics from bananas, avocados, prawns, rice, sugar and seaweed...Read more
Applications of BioPlastics
Disposable cutlery and other consumer products Source: bioplastic.com
Applications vary from mulch film to 3D printing Source: https://labiotech.eu/
Bioplastics are used in disposable items like packaging, containers, straws, bags and bottles, and in non-disposable carpet, plastic piping, jewellery, phone casings, car insulation and medical implants.
Are BioPlastics Biodegradable?
Biodegradable means that it can be broken down biologically. This involves breaking down the bonds of the polymers.

Only SOME bioplastics are biodegradable.

They need soil or aquatic environments to degrade in. In soil, they need higher temperatures and in water, they affect marine organisms.

Some bioplastics can be completely converted to carbon dioxide and water by microbial action.

HOWEVER, biodegradable bioplastics only effectively and completely biodegrade in an industrial facility and a controlled environment. If thrown out into the landscape, they may not degrade on their own.
Well..Are they Compostable?
Compostable means that a material finally gets converted into compost or humus.

For a material to be compostable it cannot have any inorganic residue.

Not all bioplastics are compostable and most require industrial conditions to compost.

They will likely NOT turn into compost in your backyard composting pit.
To know more on bioplastic biodegradability, click here
So ... are they good or bad for the environment?
The good news is that ...
  • They reduce the amount of fossil fuels we use for plastics.
  • They emit less greenhouse gases than plastics.
  • Some of them are biodegradable
Unfortunately...
  • They pollute water bodies
  • Increasing acidification of soil.
  • The biomass they are made from demands land that can be used to grow foods.
  • They also are not able to completely replace petro based plastics.
While bioplastics are generally considered to be more eco-friendly than traditional plastics. A study from the University of Pittsburgh in 2010 found that bioplastics production resulted in polluting the soil, due to the chemical fertilizers and pesticides used in growing the crops and the chemical processing needed to turn the biomass into plastic.

         While as many believe bioplastics to be biodegradable, most require high temperature industrial composting facilities to break down and very few countries have the infrastructure for this. As a result, bioplastics often end up in open garbage dumps where they may release methane, a greenhouse gas more toxic than carbon dioxide.

             When bioplastics are not discarded properly, they can contaminate batches of recycled plastic and harm recycling infrastructure as separate recycling facilities are required for bioplastics. The manufacture of bioplastic again requires large areas to be harvested for its manufacture and this land  ultimately competes with food production.
 
A comparative study of bio plastics and their limitations
Source: http://www.bioplastics.guide
To know more on the advantages and disadvantages of bioplastic, click here
Which countries are manufacturing bioplastics on a large scale?
The global bioplastic production was around 1.7 million tones in 2014. Out of which 0.7 million could be attributed to bioplastics of PLA, PHA and starch blends. Packaging still remains the major use of bioplastic making up 70% (1.2 million tones) of the total being used.  

The bioplastic market in India is steadily but surely growing. India has the raw material biomass required for bioplastics in abundance. Quite a few manufacturing firms like Envigreen, Ecolife, Plastobags, Earthsoul India and Truegreen have come up with different forms of bioplastics, which are already supplying these environment friendly forms of plastics in regional markets.
Bioplastics might be a better option than the conventional plastic and are a step forward in the evolution of materials. To replace the convenience offered by petro based plastics while ensuring that the material is entirely biodegradable is the goal towards which bioplastics are headed. However a lot more refinement is required before they can totally replace petro based plastics.