Is ABS Plastic Biodegradable?

  • By: greenorb
  • Date: April 23, 2022
  • Time to read: 5 min.

ABS plastic is a popular component among many industries. It is affordable, reliable, and boasts resilient structural properties. 

That’s why ABS is an ideal choice for a wide range of industrial applications like 3D printing.

But is ABS plastic biodegradable? No, ABS plastic isn’t biodegradable. 

ABS comprises more robust materials that microbes like fungi and bacteria can’t break down into simpler molecules.

So ABS plastic will end up in landfills unless it gets recycled.Here, we’ll determine if ABS plastic is biodegradable. 

If not, is it recyclable? You’ll find all the answers you’re looking for in this article.

What is ABS Plastic?

ABS in full means acrylonitrile butadiene styrene. It is a polymer plastic sourced from petroleum products. 

ABS is also a type of plastic that exists as an amorphous polymer and an opaque thermoplastic.

ABS as a Thermoplastic Compound

It is thermostatic because this type of plastic reacts to heat differently. When you heat ABS plastic at temperatures of 2210F, it melts into a liquid.

The liquid can cool into solid form, which you can reheat again without damaging the plastic’s chemical structure.

ABS plastic doesn’t burn. The plastic melts into liquid form and cools to get back to its solid-state.

This process can occur very many times, making ABS plastic is an excellent choice for recycling than thermoset plastics.

Why is that? The reason is that thermoset plastics can get reheated only once.

ABS plastic as an Amorphous Compound

This type of plastic is an amorphous compound as it doesn’t follow the regular steps like other ordered materials. 

ABS plastic doesn’t change from solid to liquid upon reaching a specific temperature.

It also doesn’t have a real melting point, but it has a glass transition temperature of 1050C. 

This is the temperature at which ABS plastic changes from solid to rubber or an elastic-like state.

ABS as a Terpolymer

ABS comprises three different polymers, each occupying a certain percentage of plastic. These are:

  • Acrylonitrile: 15-20%
  • Polybutadiene: 5-30%
  • Styrene: 40-60%

Each polymer has unique properties that combine to form the overall characteristics of ABS plastic. 

Acrylonitrile gives the plastic strength, rigidity, and hardness. The polymer also makes the plastic resilient to mechanical stress.

Styrene adds to ABS’ glossiness and permeability. The polymer also adds to the plastic’s rigidity and hardness.

Polybutadiene mainly makes the plastic material tougher and more flexible.

Is ABS Plastic Biodegradable?

For a material to be biodegradable, it can undergo decomposition. Oxygen and heat must be available for the process to occur effectively.

Microbes such as fungi and bacteria, including other microorganisms, act upon such materials.

The sad news is that ABS plastic is non-biodegradable. 

That’s because ABS exists as the strongest type of plastic. The plastic comprises three polymers that contribute to its impressive rigidity.

It means that nothing else except high temperatures can shake ABS’s structural composition. Even decomposers can’t break down this type of plastic naturally, making it non-renewable.

According to the Ecological Engineering journal, ABS plastic may slightly decompose. But that will take up to 500 years or even more.

As for biodegradable plastics, it may take them a very long period to decompose in the environment by natural means.

Is ABS Plastic Recyclable?

While ABS plastics are non-biodegradable, they are recyclable. Recycling is the best way to reduce ABS plastics ending up in landfills which may cause environmental degradation.

ABS is well-known for its durability facilitated by its rigid physical properties. 

The plastic is a product of polymerization of three different polymers, contributing to ABS’s resilient nature.

Acrylonitrile offers plastic strength; butadiene makes it more rigid and durable. Styrene adds toughness and luster finish. 

These three polymers give ABS unique structural properties that microbes can’t break down.

That’s why recycling comes as the best candidate for managing this resilient plastic.

The good thing is that recycling centers are available to help make useful products from old ABS plastics.

How is ABS Recycled?

The ABS plastic recycling process includes the following stages:

1. Segregation

ABS must first get separated from other plastics, debris, and contaminants. At the industrial level, the separation occurs through froth flotation.

The process involves using an oil-water mixture with impure ABS to separate the plastic from other particles.

At the municipal and home level, segregation will occur at the collection stage. The ABS plastic will get transported in a container.

2. Grinding

The components of ABS will then get crushed into granular form. An industrial grinder or consumer grinders come in handy at this stage.

3. Melting & Reforming

The granules get fed into an extruder to melt and reform the ABS plastic. 

Depending on the job of the extruder, you can expect to get recycled ABS plastic which comes as plastic filaments or sheets.

Granules from ABS plastic may also enter a proper injection molding unit to melt and form new products.

But the problem is that most recycling facilities don’t accept ABS plastics for recycling. 

These plastics have an incredibly rigid structure, which requires higher temperatures to melt them down.

It becomes a challenge for most plastic recycling facilities to accept ABS plastic with such requirements. They also claim that the final product formed will have low quality.

And these plastics end up in landfills, resulting in environmental degradation.

So what is the Way Forward?

Finding an alternative to the non-biodegradable ABS plastic is the best option. But do we have any alternative to ABS? illustrates how researchers are closer to founding a new biodegradable product. But it may have similar properties as ABS plastic. 

The unnamed green alternative comes from carbon dioxide, palm oil, and starch. 

Further research by the Department of Energy’s Oak Ridge National Laboratory (ORNL) claims that the new bioplastic outperforms ABS plastic.

Final Thoughts

Is ABS plastic biodegradable? No. ABS plastic comprises a stronger physical structure formed due to blending three different polymers. 

These chemical compounds add to the resilient nature of ABS plastic, making it non-biodegradable by microbes.

Even if ABS could decompose, the process would take hundreds of years. The best way to deal with this type of plastic is to recycle it.

However, not all recycling units accept ABS plastic because of the complexity involved in recycling them. 

That leaves us with the option to look for an alternative to ABS, which is not yet fully discovered.