With consumer demand for green alternatives, biodegradable plastic has become a popular alternative material. But if it really does play a big role in mitigating pollution, then why aren’t we promoting its use in large quantities?
Difficult to biodegrade
Most synthetic plastics are not naturally evolved and cannot be widely digested as food for animals and microorganisms; Biodegradable, as we understand it, is not something that is discarded into the environment and then degrades naturally after a period of time.
Many plastics that are considered biodegradable only degrade when certain conditions are met, and they generally do not degrade as expected if the conditions are not met. For example, PLA, the most abundant type of degradable plastic, is only degradable under industrial composting conditions(which are few and far between); otherwise, PLA does not degrade quickly. If a PLA bottle is thrown into the sea, it takes hundreds of years to be decomposed.
Difficult to recycle
A prerequisite for achieving complete degradation is the separation of biodegradable plastic from the ordinary.
In the current waste sorting, it is difficult to effectively distinguish between degradable and non-degradable, but mixed together for disposal. This disposal can only be treated as ordinary plastic recycling, not only can not be effectively degraded but also increased the difficulty of recycling ordinary plastic.
Therefore, “biodegradable” is only “can be degraded”, not the same as “true degradation.
Not good performance
Biodegradable plastics cannot maximize various functional requirements, such as being easy to mold, having the required strength and durability, and then requiring to degrade and disappear as soon as possible after use, this is contradictory.
Expensive
The cost of biodegradable plastic is 5 times more expensive than ordinary plastic (PLA is more than $3,000/ton), while PET only needs $600/ton), but the durable and long-lasting performance is only 1/5 of ordinary plastic. and raw materials are often in short supply.
The expensive price brings reluctance to use, do not want to use, can not use. Large companies can be well managed, but smaller companies are difficult. Once the price increases, customers are reluctant to come.
The 3R Principle
At present, global environmental protection agencies are cautious about the development and promotion of biodegradable plastics. It is a global consensus that we need to take the path of a plastic recycling economy to control plastic pollution.
To solve this problem, the international universal principle is the “3R”: Reduce, Reuse and Recycle. The first two principles are to reduce the use of plastics, and the third is post-consumer recycling, including physical recycling and chemical recycling. Biodegradable plastics are not an alternative to plastic recycling and are still only a supplement under limited conditions.
