Types Of Bioplastics

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The first bioplastic was discovered by Maurice Lemoigne (French Researcher) in 1926, but due to the abundance of synthetic plastics during that time, it didn’t gain popularity. 

However, after 1970, researchers all over the world started finding alternatives to petroleum-based synthetic plastics. Now, in the 21st century, it’s a very prominent substitute for traditional plastics.

What are Bioplastics?

Bioplastics are a type of plastic derived from renewable biomass, agricultural by-products, and used plastics with the help of microorganisms. These plastics are either biodegradable or bio-based or could have both properties.

These plastics are typically produced from sugar derivatives like cellulose and starch. However, it can also be derived from straw, milk, tapioca, sawdust, wood chips, food waste, vegetable oils and fats, etc.

Do all bioplastics biodegrade?

It is assumed that since bioplastics are ‘bio-based’, they are biodegradable. However, this is not valid for all bioplastics.

Biodegradation is a process wherein the microorganisms present in the environment converts the materials into a natural substance like carbon dioxide, water, methane, and so on. Also, the material is biodegradable when it degrades in a short period of less than one year.

Thus, bioplastics derived from polylactic acid and plant-based cellulose that breaks down entirely within a few months are biodegradable. On the other hand, plastics like bio polyethylene and bio-MEG, which take a few years to degrade, are known as “durable” yet are not biodegradable. 

Uses of Bioplastics

Bioplastics have various advantages over petroleum-based plastics as they are renewable and eco-friendly. Over the past decade, there has been a drastic surge in the application of bioplastics. Some of the uses of bioplastics are:

Packaging

Image Source: European Bioplastics
In the packaging industry, conventional plastics are considerably replaced by bioplastics. Bioplastics packaging includes bags for shopping, waste collection, agricultural foils, nursery products, horticultural products, textiles and toys.

Besides packaging, bioplastics are also used to manufacture disposable cutleries like cups, plates, salad bowls and food containers.

Consumer durable industry

The durable consumer industry has now begun to use bioplastics to tackle its environmental impact and improve its credentials.

Currently, electronic circuit boards, product casings and data storage are all made from oil-based plastics. Few consumer electronics companies are also looking forward to manufacturing products like headphones, touch screen computer cases, keyboards, laptops, game consoles, vacuum cleaners and loudspeakers using bioplastics.

Medical Equipment

Non-toxic bioplastics are now used as stitches by various doctors all over the world. Bioplastics stitches are robust and are dissolved without leaving marks behind.

Biodegradable plastics are also used for medical equipment like tacks, pins and screws, which are used in the process of healing bones and surgery related to dermatology. Dentists use these kinds of plastics for dental implants and tooth filling.

Automotive and aerospace

Transportation, especially aeroplanes, are the most significant contributors to carbon emission. Thus bioplastics are now used in this industry as they have the same properties as synthetic plastic

Another reason for the usage of biodegradable plastics for both sectors is its vital temperature resistance characteristic.

Cosmetics

Image Source: European Bioplastics
The cosmetics industry uses bioplastics for packaging its products. Disposable body and hair care products like toothbrushes, cotton buds, hairbrushes and razors end up in landfills and do not biodegrade. Hence industries producing these products are starting to look at bioplastic as the alternative.

Types of Bioplastics

Bioplastics can be of various types, which is based on the source that it has been derived from. The most common plastics used presently are:

Cellulose-based Bioplastics

Cellulose plastics are derived from cellulose acetate, nitrocellulose and cellulose esters. These kinds of cellulose are present in plant materials like forestry residue and by-products of agricultural production.

Researchers and scientists worldwide are currently figuring out how to extract cellulose efficiently from model feedstock, leaves, stalks, tassels, and husks left after harvesting and then adding inorganic salts to separate the cellulose.

Starch-based Bioplastics

Starch plastics are the most common type and widely used bioplastic, and it constitutes approximately 50% of the bioplastics market. It could also be prepared at home by following processes like ‘gelatinizing starch’ and ‘solution casting’.

Pure starch plastics are brittle but it absorbs humidity from the environment. That’s why it is used in the pharmaceutical industry for producing capsule covers.

Starch plastics films are also used in the packaging sector for packing consumer goods, bakery items, fruits and vegetables and magazines. These films can also be used as paper.

Protein-based bioplastics

Protein-based plastic is made from various sources of protein like soy, albumin, wheat gluten, etc.

Out of the above protein sources, soy protein plastics have been produced for more than 100 years. The best example of the application of soy protein plastic is the body panels used in Ford automobiles. Another usage of protein bioplastics is the films that are used in the packaging industry.

However, protein-based plastics are water-sensitive and expensive but the addition of biodegradable polyesters reduces the cost and water sensitivity of these plastics.

Aliphatic polyesters bioplastics

Some polymers of esters like polyhydroxyalkanoates (PHA), poly-hydroxy-hexanoate (PHH), poly-3-hydroxybutyrate (PHB) and poly-hydroxy-valerate (PHV) are bio-based or aliphatic and are used to make plastics.

Aliphatic polyester bioplastics are highly biodegradable and biocompatible and usually have a high melting point. Though these kinds of plastics are brittle, blending them with other polymers makes them robust and strong.

Polylactic acid (PLA) Bioplastics

It is a kind of PHA plastic that is transparent and derived from sugar like dextrose or maize. It is generally available in the form of granules and is used for producing fibres, films, plastic containers, bottles and cups.

Poly 3- HydroxyButyrate (PHB) bioplastics

These aliphatic plastics are derived from a few bacteria processing corn starch, glucose or wastewater. Its production has drastically increased in recent years, especially in South America.

It is also transparent with a high melting point and doesn’t leave any residue when degraded. However, the production cost of PHB plastics is relatively higher.

Polyhydroxyalkanoates (PHA) plastics

Another type of aliphatic bioplastics is PHA plastics which are derived naturally by fermentation of lipids and sugar. This kind of plastic is less elastic and malleable as compared to other biodegradable plastics.

Polyhydroxyalkanoate plastics are used in the medical, textile and packaging industry. These plastics have high production costs.  

Polyamide 11 Bioplastic

Polyamide 11 or Nylon 11 plastics is a member of the nylon family produced from natural oils. These kinds of plastics are not biodegradable, but during its production, it emits fewer greenhouse gases.

Polyamide 11 plastics have a broader application and it is used in industries like oil and gas, textiles, consumer electronics, sports, automotive, aerospace, metal coatings and electric.

These plastics have high performance and high electrical resistance.

Bio-derived polyethylene

Bio-polyethylene or renewable polythene is derived from Ethanol, which converts to ethylene after a dehydration procedure. Ethanol can be obtained from sugar beet, corn, sugar cane and wheat grain.

This plastic is non-biodegradable and has the same physical and chemical characteristics as synthetic polythene. It is used in flexible and rigid packaging, bags, closures and various other products.

It emits comparatively less CO2 in its production as compared to petroleum-based polyethylene.

Polyhydroxy Urethane Plastics

When cyclic carbonates and polyamides are condensed, it produces Poly Hydroxy Urethanes. It is used in making foams, sealants, adhesives, coatings, insulation of refrigerator, mattress, car parts, paints, tires, shoe soles, wood panels, and sportswear.

Genetically modified bioplastics

These are the bioplastics that are derived naturally by few species of bacteria. The bioplastic produced in genetically modified plants is very flexible and is biodegradable. It is commonly used in packaging industries.

Current trends and Market size of Bioplastics

Photo by Markus Winkler on Unsplash

In the present scenario, bioplastics represent approx 1% of production out of 368 million tonnes of total plastic produced annually. However, the growth rate of the bioplastic market is seeing a rapid uptrend, and it will reach close to 2.7 million tonnes by 2025.

Bio Polyethylene and bio Polyethylene Terephthalate are the main types of bioplastics that are responsible for the growth.

Bioplastics are in high demand in shipping packaging companies as they require sturdy and sustainable plastic which are fit for bearing heavy loads. Besides the shipping packaging industry, there is an increasing demand for bioplastics in food and pharmaceutical companies.

Geographically, the bioplastic industry is dominated by European countries, which have a current market share of 19% and are expected to reach 25% by 2022.

The major players in manufacturing bioplastics are Kaneka Takasago, Taghleef Industries, Genesis, Toray, Roquette, Succinity GmbH, NatureWorks, Danimer Scientific, Biofase, Bioapply, Avantium and Matrica.

Final Words

We hope that this article is beneficial for bioplastics knowledge and their application. We should embrace bioplastics as an alternative to synthetic plastic and make the environment more sustainable, cleaner and greener, particularly in the world’s rivers and seas.

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