Bioplastics are obtained from renewable plant resources. Examples; corn starch, sugar beet, straw bale, wood chips, food scraps. Bioplastics are usually derived from starch, cellulose and sugars such as lactic acid. As of 2014, bioplastics represented about 0.2% (300 million tons) of the global polymer market.
Synthetic polymers can be highly resistant to chemical and biodegradation. The degradation process of this material is quite long. This calls into question the use of synthetic polymers. When degraded, they leave wastes that are highly toxic to human and environmental health. For this reason, researchers are looking for raw materials that can replace synthetic polymers. In their search, they turn to alternatives that are compatible with biological processes and do not threaten human and natural health.
Bio-plastics can replace petroleum-based plastics. However, this is not valid for all sectors. Because it may create cost and performance problems in some sectors. Biodegradable plastic bags are mandatory in some countries. Italy, most states of the US, Canada and the UK are examples.
Reasons to Prefer Bioplastics
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Petroleum-based plastics have limited resources. Bio plastics, on the other hand, have a producible resource. These resources create a sustainable economy that is not limited.
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Since it is produced from biological resources, it reduces dependence on petroleum resources. As a result, it creates less greenhouse emissions.
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When used for packaging food products, they do not change their taste and odor.
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They do not contain materials that threaten human health such as petroleum-based plastics.
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Plant-based resources are used in the production of bio plastics. This means less carbon emissions than petroleum-based plastics. It also means an unlimited production resource.
What are the Types of Bioplastics?
There are some conditions for a plastic to be classified as bioplastic. These are; it is bio-based, biodegradable or has both properties. Based on this, we can categorize bioplastics under three groups. Bio-based plastics, bio-based biodegradable bags and petroleum-based biodegradable bags. The raw material of bio-based plastics is plant-based. Sugar cane is used in most industries to produce these plastics. However, corn and other plant materials can also be used on demand. The raw material produced in this way is called PLA. The other type, PHA, is made by microorganisms that produce the substance when deprived of nutrients. PHA is used in the medical field. PLA is used in the plastic packaging industry. The main raw material in petroleum-based biodegradable bags is plastic polymers. Additives are added to petroleum-based plastic packaging during production. Thus, it is made biodegradable. These additives are divided into bio-degradable and oxo-degradable. Bio degradable bags are consumed as food by microorganisms. They leave behind water, CO2 and methane gas. The situation is slightly different for oxo degradable. Oxo-containing plastic bags are broken down into very small pieces in nature. It has not been clearly proven that it degrades as a result of decomposition. Therefore, some sources use the term degradable for oxo degradable.
Disadvantages of Bioplastics
0.02% of the world’s agricultural land is used for bioplastics. This rate is expected to increase in the coming years. This expected increase is expected to pose some threats. The most important of these is that increasing demand will occupy agricultural land used for food. It will also lead to the spread of monoculture crops, with agricultural products limited to corn and sugar cane. This will damage the natural ecosystem.
How does the biodegradation process work?
Biodegradation is a process carried out by microorganisms. This process releases carbon dioxide, water and methane. We can summarize biodegradation under 4 stages. In the first stage, biofilm forms on the biodegradable packaging. The material decomposes into smaller substances. In the second stage, microorganisms break down polymer chains. Thus the packaging breaks down into smaller molecules. In the third stage, the small molecules are processed in microbial cells. In the fourth stage, a process called mineralization takes place. In this process, carbon dioxide is converted into simple molecules such as water and methane. These harmless products take their place in nature.
No clear time can be given for this decomposition process. Because this process can vary according to some factors. Examples of these are temperature, humidity and microorganism concentration.
Even if bio plastics have some disadvantages, they will be very important for nature and humanity with R&D studies. Researchers continue to work on the development of this material. They especially examine the functioning of microorganisms in different environments in biodegradation. As a result of this research, they can develop polymers compatible with microbial biodegradation. They can even synthesize new polymer materials
