Fossil based plastics have been around for as long as one can remember. However, there has been a growing concern with regard to the environmental impacts of plastics and their increasing use. Various types of bioplastics have now been invented and are being considered as a sustainable replacement to conventional plastics.
As the name suggests, these are plastic-like materials produced using organic, renewable raw materials like starch, fats, and oils from vegetables, agricultural waste, wood, sawdust, etc. Conventional plastics, however, are derived using nonrenewable fossil fuels which are an environmental concern.
Types of bioplastics
Bioplastics include a wide and growing category of biological material based polymers that have their own unique attributes and uses. With new inventions happening in the field, the list is continually expanding.
Bioplastics are usually categorized into three main groups:
Bio-based plastics– These include the bioplastics made out of bio polyesters. Polyethylene (PE), polyethylene terephthalate (PET) and certain polyamides (PA), and polyurethanes (PUR) are included in this category.
Bio-based and biodegradable plastics– These include versions like polylactic acid (PLA), polyhydroxyalkanaoates (PHA), polybutylene succinate (PBS).
Fossil based but biodegradable plastics- These include PCL, PBAT, etc.
However, the following are the most common bioplastics being used in the present day:
1. Starch-based bioplastics:
This category of bioplastics is derived using corn starch, potato starch, etc. They are sometimes mixed with biodegradable polyesters to enhance the properties of the bioplastic.
Starch is the most widely used raw material for making bioplastics. The making process is simple and can be tried as a DIY experiment within home kitchens too.
Starch based bioplastics are used in the medical industry for the production of capsules. Additionally, they are often blended with other bio polyesters to create high strength bioplastics that can be used for commercial applications.
Starch-based bioplastics are also considered cost-efficient since the raw material, that is, starch is cheap and abundant in availability.
2. Cellulose-based bioplastics:
These bioplastics are created using cellulose esters and derivatives made from cellulose. Cellulose is also added to starch to create biopolymers that have enhanced mechanical properties and are highly water-resistant too.
3. Protein-based bioplastics:
Various protein sources like wheat gluten, soy protein, milk, and casein are great sources of producing bioplastics.
4. Aliphatic polyesters:
There are various types of bio-based polyesters which are collectively known as Aliphatic polyesters. These include:
- Poly-3-hydroxybutyrate (PHB)
- Polyhydroxyalkanoates (PHA)
- Polyhydroxyvalerate (PHV)
- Polyhydroxyhexanoate (PHH)
- Polylactic acid (PLA)
- Polyamide 11 (PA11)
5. Bio derived polyethylene:
Also known as organic polyethylene (PE), these are usually produced by fermenting raw materials from agricultural produce like sugar cane, corn, etc.
Ethylene, which is the monomer that creates PE, can be derived using ethanol and other fermented waste from agricultural products. The bioplastic, hence formed, is similar in chemical and physical properties to conventional polyethylene.
Bioplastics have replaced fossil fuel-based plastics in various industrial and everyday applications.
The use of bioplastics in disposable food packagings, crockery, pots, straws, and bags is common in various countries across the globe.
While it is true that various bioplastics compete with conventional plastics in terms of strength and durability, the practicality of their use in commercial applications has various other concerns.
The cost of production is one of the biggest concerns. That said, various countries are now working towards creating financially favorable models for large scale use of bioplastics.
Common bioplastic recipes
Plastic products have widespread industrial as well as daily life applications. Looking at the growing issues regarding plastic waste accumulations, companies across the globe have been experimenting to create alternatives that can substitute the lightweight, low-cost values of conventional plastics.
Different types of bioplastics are now being considered for multiple applications.
Starch-based bioplastics, as mentioned earleir are the most commonly used ones and constitute about 50% of the global bioplastic market.
The raw material like corn is readily available, cheap to procure and can be conveniently sent to the landfill for disposal.
Additionally, the bioplastic is extremely simple to create. So much so that the recipe can be made right within the walls of your kitchen!
Read on for one of the simplest bioplastic recipes.
- Cornstarch (1 tablespoon)
- Vinegar (1 tablespoon)
- Glycerin (1 tablespoon)
- Water (4 tablespoons)
Measure all the aforementioned ingredients in the specified quantities or equivalent ratios. Mix them in a cooking pot. Stir them together and turn the stove heat to medium or low.
Stir regularly to avoid lumps. The mixture will soon start turning translucent (from its original milky color). Let the heat remain at low to avoid burning of the material.
Turn off the heat after about a minute or more. Stir some more and pour the mixture on an aluminum foil. Spread it on the foil with a spatula.
Let the plastic harden for several hours. You can also pour it on the desired shape to get the effect.
Other methods like making bioplastics using Gelatin and Agar, etc are also easy to create and are commonly used.
Various new inventions and interesting pieces of research have come up in the last decade for making bioplastics. One of the notable ones has been the production of bioplastics using algae.
Algae bioplastics are the most recent update in the world of bioplastics. While the production and use of algae bioplastics are still in an infancy stage, the future is bright. Ongoing research shows very promising results. Commercialization of algae bioplastics for usage in multiple industries/sectors can soon be expected.
The use of algae for bioplastics
Bioplastic production is dependent on source materials. Renewable sources like vegetable oil, corn starch, potato starch, etc have been used successfully for the development of bioplastics.
However, the search for better raw material sources that give higher yields in multiple environmental conditions has been ongoing. Algae bioplastics one of the most accepted research solutions in the world of modern bioplastics.
Algae are an excellent raw material for the production of bioplastics. This is largely because of the multiple advantages that they offer in comparison to other feedstock material. The ability to give a high yield in varying environmental conditions is one of them.
Additionally, algae biofuels are already being used by multiple companies. The bi-products of these processes can be used to produce algae bioplastics.
The use of algae has also been considered particularly beneficial for the environment. The production of algae bioplastics helps in utilizing carbon, thereby reducing the overall greenhouse gas percentage from the environment.
Types of algae bioplastics
The source of bioplastics is broadly classified into the following:
- Plant and animal sources: these include lipids, fats, starches, protein, etc.
- Polymerizable molecules from renewable resources: These include lactic acid, triglycerides, etc.
Algae feedstock can be utilized to produce the following types of plastics:
1. Hybrid plastics
As the name suggests, these plastics are a hybrid made out of algae biomass and conventional petroleum-based plastics. Raw materials like polyurethane and polyethylene are taken up as fillers and algae biomass is then added to it. The overall amount of petroleum needed is hence reduced.
Additionally, the resultant plastics have more desirable properties than their conventional counterparts.
Filamentous green algae are the most commonly used ones for producing hybrid algae plastics.
2. Cellulose-based plastics made out of Algae
For various strains of algae, the biomass produced when algal oil is extracted contains a substantial amount of cellulose. These algae are hence used as feedstock for cellulose-based plastics. These show typical characteristics like other cellulose plastic versions.
3. Polylactic acid
Lactic acid is a commonly used raw material for the production of bioplastics. The polymerization of lactic acid results in the production of polylactic acid (PLA) which is a biodegradable version.
Lactic acid based bioplastics are more economically viable than conventional plastic. However, using lactic acid produced as a result of algae fermentation is considered one of the most cost-effective options.
4. Bio polyethylene
Biopolyethylene is derived from ethylene which in turn is produced from ethanol. Ethanol is an alcohol that is usually derived from natural gases and petroleum products. However, ethanol can also be produced as a result of bacterial fermentation of algae biomass.
The use of easily available and renewable raw materials makes the production of bioplastics an environmentally friendly and sustainable method.
The shift from conventional plastics to bioplastics can help organizations worldwide to work in an environmentally sustainable manner. And with the availability of different types of bioplastics and upcoming experiments in the field, the shift is completely possible. In fact, it is definitely the way to a greener future.