BioPlastic Myth and Reality

 Introduction

There is always confusion among most of the people about bioplastic and biodegradable plastic. Most of the people make mistake by considering bioplastic are same as biodegradable plastic. The bio based plastics are plastics made from biomass, generally related to the use of plants as feedstock. Given their natural origin, one could erroneously assume that these plastics are also biodegradable. However, biodegradability depends on the properties of the plastic at hand, including chemical structure and crystallinity.

Polymers are derived from bio-based monomers that subsequently undergo chemical reactions to become bio-based polymers. For Example

1.       The bio polyesters PLA and PEF,

2.       Sugarcane-based bio polyethylene,

3.       Nylon 4/10 and 11, which are derived from castor oil.

Bio Based polymers are naturally occurring polymers such as Cellulose, Polysaccharides, Starch, Protein.

Background

The first known bioplastic, polyhydroxybutyate, (PHB), was discovered in 1926 by a French researcher, Maurice Lemoigne, from his work with the bacterium Bacillus megaterium.

Henry Ford, Ford Motor co., in 1930, had started experiment led to the development of soy-based oils and plastics for use in vehicles. But due to WW II research in this area has stopped and post war cheap and plentiful petroleum brought down the cost of manufacturing plastics based on oil.

Want to know more information about Biodegradable Plastic 

Source of Bioplastic

In the majority of cases, bioplastic today are obtained from biomass, they are therefore called biobased  Certain biodegradable polymers are still obtained from fossil fuels, but only a few (PBAT and PCL primarily).

The biomass used for manufacturing biobased polymers is predominantly renewable and sourced from different activities like agriculture or the agro-food industry. In the various steps of processing the biomass, bacterial fermentation of sugars from various origins is the key point. It is through these procedures that the building block molecules for green chemistry are obtained, which can be used as monomers for producing biobased polymers.

Different categories of bio plastic

a.      1^St generation ( Food )

                                                   i.      Vegetable Oil –Soybean, Palm Oil, Sunflower, etc

                                                   ii.      Starch :- Corn, Wheat, Potato etc

                                                   iii.      Glucose:- Sugarcane, Beet Root

b.      2^nd Generation  ( Non-Food)

                                                       i.      Cellulose :- Wood, Bagasse,

                                                      ii.      Non Food Oil: caster Bean

c.       3rd Generation (Non Food soil-less farming)

                                                       i.      Sugars or Oils produced from micro- organism:- Microalgae, bacteria, mushroom, yeast etc

                                                    ii.      Municipal waste:- organic waste.

Today, the main resources are from cereal resources (cornstarch or hydrolyzed wheat) or directly obtained from the sugar industry (sugarcane, beetroot, and molasses) or from vegetal oil such as castor oil.

The amount of land this required at the end of 2017, according to calculations by European Bioplastic, equaled 0.016% of the global agricultural area.

"Even with the predicted high growth rates of the bioplastics industry over the next years, the land-use share would only slightly increase to up to 0.021% of the agricultural area by 2022," says the association.

Manufacturers of bio-based plastics are exploring the use of other biomass sources -lignocelluloses, sewerage, methane, nonfood crops and agricultural by products and food crop waste. And a group of leading global brands, including Coca-Cola Co., Danone, Ford Motor Co., H.J. Heinz Co., Nestle, Nike Inc., Procter & Gamble Co. and Unilever, have set up the Bioplastic Feedstock Alliance to support the responsible development of plastics made from plant material and help to build a more sustainable future for the bioplastics industry.

Second- and third-generation feed stocks are expensive to process, requiring more energy and more resources.

Why to push biobased plastic?

    There is always question, if this not biodegradable plastic then why to push such plastic at all? Michigan state University professor Ramani Narayan explained that bio-based plastics make sense because of the inherent value of reducing the carbon footprint of plastic materials. What is more, plant biomass is renewable and grows everywhere, creating opportunities for rural, agrarian economies.

Degradation Process

A common misconception is that biodegradable means that a product made from these materials will somehow disintegrate spontaneously in the environment. The fact is most bio-based biodegradable plastics will degrade only under specific conditions such as those found in industrial composting facilities.

Some types have been engineered for home composting. A small number of companies have developed a few PHA grades said to be marine-degradable. Danimer Scientific announced the development of the first fully marine biodegradable plastic straw in September 2018, while Bio-on SpA produces a PHA product designed to replace microplastic beads in cosmetics.

Biodegradable bio-based plastics are emphatically not the solution to plastic waste, litter or the plastic soup. Where they are useful are in applications where biodegradability is functional — think mulch films — or in single-use food packaging, which is often too contaminated to be adequately recycled.