How does PLA fare as a biodegradable material? Find out if PLA is an ideal alternative to other polymers and how long it takes for it decomposes.
Poly (lactic acid) or PLA is a biodegradable polymer with multiple industrial applications and functions. This type of plastic is manufactured from various starch types derived from plant sources like sugarcane and corn. PLA is categorized as a thermoplastic.
Thermoplastics have high tensile strength and overall durability. The best thing about PLA is it can be manufactured from purely sustainable feedstock. PLA is routinely used in the medical device industry, specifically for bioabsorbable medical devices and applicators.
The base of this biodegradable polymer is lactic acid. Lactic acid undergoes several processes, including bacterial fermentation. A lactide dimer is eventually produced with high molecularly density that remains lightweight and handy when used for manufacturing different objects. The polymerization process does not require the use of water.
Is PLA Environmentally Friendly?
Is PLA biodegradable or compostable?
In a nutshell, we can say that PLA is more environmentally friendly than other plastics. Since it belongs to the ground of biodegradable polymers, it is far friendlier to the Earth than conventional plastics like ABS that have no chance of degrading in the next 100 years or so.
ABS plastics require 500-1000 years to decompose fully, and many of us won’t be around when that happens. This problematic nature of plastics keeps plastic researchers on their feet because we are producing tons of plastic yearly, and a portion of the plastic keeps finding its way to waterways and the oceans.
Let’s talk about how PLA biodegrades over time. PLA’s natural decomposition is highly reliant on the external environment. PLA is made from corn, but it does require some time before fully breaking down. Not all PLA is molded to become bio-absorbable medical devices, so don’t expect all PLA products to behave the same way as bio-absorbable medical devices that deliver medicine to humans.
Three main factors affect the speed at which PLA breaks down: temperature, humidity, and the right microbes that break down the polymerization and render PLA into biomass form. If we are talking about PLA’s visible degradation, if the right factors come together, you can expect PLA to begin breaking down within 12 months of disposing of it.
You might be wondering: would PLA suddenly decompose if you are still using it? This isn’t likely because microbes’ presence is limited when an object is still in human habitation, and most residences are climate-controlled, so that controls exposure to heat, UV rays from the sun, and excessive humidity.
However, all of these factors exist in a dump or an industrial facility for composting or recycling. High heat and humidity will eventually break down PLA as has an organic core, much like corn where it originates from.
The ideal scenario for PLA to decompose quickly is if it is a high-temperature area and different microorganisms are abundant on the Earth.
The bacteria will wear down the polymerization and process the PLA so it can finally be broken down into base substances. The required temperature is a minimum of 60°C before PLA begins breaking down. 60°C is also called the glass transition point for PLA.
If you have PLA at home in the form of 3D prints that have gone bad or PLA supplies that you no longer need, you need to dig a deep enough hole so you can bury the PLA. T,
his will result in much faster degradation of the PLA. In six months, the PLA will begin to show visible cracking, and soon after, the Earth will reclaim it. One year is much better than 1000 years, right, so be patient while waiting for the PLA to decompose.
Does PLA Biodegrade in The Ocean?
Is PLA biodegradable in the ocean?
Currently, there is no evidence that PLA will degrade quickly in marine conditions. It will eventually degrade due to the presence of heat (though this is much lower than the ideal) and bacteria. Due to the requirements of degradation, PLA must not be thrown into the ocean but should instead be buried into the Earth, where microbes in the Earth can safely break it down.
How Long Does PLA Take to Decompose?
The average decomposition time for PLA is 12 months or one year. Decomposition or degradation at room temperature is still possible, but the process is incredibly slow compared to more ideal conditions where the PLA is buried into the Earth. In a regular residential or office environment, PLA will resist degradation and would function as a stable and durable polymer.
This is important, on the other hand, as PLA is used for medical devices and other functional items. Keep in mind that ordinary exposure to sunlight will not speed up the decomposition of PLA because it’s the bacteria that will make easy work of this degradable polymer. Regular exposure to sunlight will only change the color of PLA.
Is PLA Toxic to Breathe?
Is PLA toxic?
In solid form, PLA poses no harm to humans. It is used in absorbable medical devices, so it’s not toxic or poisonous when in a stable form. However, if you are going to ask if PLA releases potentially toxic gases when heated and applied in situations such as 3D printing, then we have to say, yes, there might be some health risks.
PLA produces VOCs or volatile organic compounds during the 3D printing process. Studies of plastic off-gassing have been around since the 1990s. ABS plastics produce the worst quantities of toxic gases when heated.
However, PLA is no exception to the rule. Scientists state that heating PLA to 200° Celsius or more will release volatile compounds into the air that are harmful to humans. Don’t worry for the most part, this will be a problem if you live in a space where there are plenty of 3D printing activities around. Otherwise, solid PLA is safe to hold, use, and generally be around you.