What are Bioplastics and Biobased Polymers?

In this guide, we will explore:

• What are bioplastics?
• What are some types of bioplastics?
• Do bioplastics actually biodegrade?
• How long do bioplastics take to decompose?
• Are bioplastics recyclable?
• What are the upstream benefits to using bioplastics?
• What are the downsides to using bioplastics?

What are bioplastics?

Bioplastics are plant-based plastics derived from renewable and sustainable materials like corn or vegetable oils. They provide a natural substitute for regular plastics made from fossil fuels that contain harmful chemicals.

One notable advantage of bioplastics lies in their ability to breakdown. They are more environmentally friendly because they can be composted which decreases the amount of waste generated. In contrast, regular plastics can persist for hundreds of years, contribute to the long term plastic waste problem (plastic straws and plastic bags are big offenders). This waste poses a threat to wildlife and human health.

What are some types of bioplastics?

Bioplastics offer a diverse range of options, each with its distinct features and uses. Here are some common biobased types of plastic:

PLA (Polylactic Acid) is a clear and flexible material made from plants like corn, cassava, sugar cane or beets. Many industries use it widely including food packaging, medical devices, and 3D printing.

PHA (Polyhydroxyalkanoates) is a biodegradable polymer with a broad range of applications, including packaging, medical products, and agricultural films. Known for excellent biodegradability, breaking down in various environments like soil, water, and industrial composting facilities.

tPLA (Talc-filled Polylactic Acid) is a natural mineral-enhanced version of PLA, tPLA offers improved heat resistance and rigidity. Ideal for applications requiring higher temperature resistance, such as disposable hot cup lids and utensils.

cPLA (Crystallized Polylactic Acid) is a crystallized form of PLA. People commonly use it to make cutlery, containers, and foodservice products. Made for extra rigidity and heat resistance, it can withstand higher temperatures compared to regular PLA.

VNPLA (Vinylized Polylactic Acid) is a film for enhancing flexibility and impact resistance. Suited for applications like flexible packaging, films, and coatings.

PHB/PHBH (Polyhydroxybutyrate/Polyhydroxybutyrate-co-hydroxyvalerate): Produced by bacteria, PHB and PHBH are biopolymers recognized for their exceptional biodegradability and mechanical properties. Suitable for a variety of applications, including packaging, disposable items, and medical products.

These examples each perform a specific purpose in meeting the demand for eco-friendly materials.

Do bioplastics actually biodegrade?

People view bio-based plastics as sustainable compared to regular plastics because they can be breakdown. However, it's important to know that not all bioplastics break down the same way or in the same conditions.

Biodegradability refers to a material's natural breakdown into harmless substances, facilitated by microorganisms such as bacteria or fungi. Some bio-based plastics break down under specific conditions, while others require the controlled environment of industrial composting facilities or specific temperature conditions.

Distinguishing between compostable vs biodegradable is crucial. Biodegradable materials naturally decompose over time, while compostable materials specifically break down with the heat of a composting environment, transforming into nutrient-rich soil. The rate of either method can vary depending on factors such as temperature, humidity, and the presence of microorganisms.

Many certified compostable bioplastic products do not biodegrade fast enough to reduce waste. Additionally, any bioplastics will not degrade in landfills so proper disposal is crucial for end-of-life benefits.

How long do bioplastics take to decompose?

Bioplastics break down at varying rates, influenced by factors like their type, environmental conditions, and disposal methods. Biodegradable plastics break down faster than traditional plastics such as PET or PP. These fossil based plastics can remain in the environment for hundreds of years.

Microorganisms like bacteria and fungi fuel the breakdown of bioplastics, transforming them into simpler, non-toxic substances and reducing their environmental impact. 

Factors like temperature, humidity, and the presence of microorganisms play key roles in decomposition. Higher temperatures and moisture levels speed up the process, while colder or drier climates may slow it down. 

Additionally, material thickness and bioplastic composition affect decomposition, with thicker materials taking longer to break down and additives influencing biodegradability.

Are bioplastics recyclable?

While some facilities may accept bioplastics for recycling, they are not widely accepted. Recycling bioplastics is not advised primarily due to contamination. For example, If bioplastics contaminate recycled PET plastic, the entire lot could be sent to a landfill or an incinerator. 

What are the upstream benefits of bioplastics?

Bioplastics bring significant advantages to their production processes, promoting a more sustainable and environmentally friendly approach.

1. Reduced Carbon Footprint

Manufacturers make bioplastics from renewable resources such as plants. These plants absorb carbon dioxide during growth. This lowers greenhouse gas emissions compared to traditional plastics made from fossil fuels.

2. Reduced Energy Consumption

Another advantage lies in the reduced energy consumption during bio-based plastics production. The manufacturing process typically demands less energy, involving lower temperatures and fewer chemical reactions compared to traditional production of plastic. Manufacturing Ingeo, a material used to make compostable PLA foodservice products, produces approximately 80% less greenhouse gases and uses approximately 52% less non-renewable energy (NREU) than traditional polymers like polystyrene. Note that this is true even if no composting option is available and the item must be sent to the landfill.

3. Conservation of Resources

Bioplastics utilize renewable resources, such as corn, sugarcane, or vegetable oils, which can be grown and harvested continuously. This helps to conserve finite resources like petroleum and reduces dependence on non-renewable fossil fuels.

4. Biodegradability

Bioplastics are designed to break down naturally through biological processes, either in industrial composting facilities or in natural environments. This reduces the accumulation of plastic waste and helps prevent plastic pollution.

5. Circular Economy

Furthermore, compostable plastics actively contribute to the Circular Economy by undergoing composting at the end of their life cycle. This helps reuse raw materials and reduce the amount of waste. Composting also aligns with the circular economy principles and maximizes resource efficiency.

What are the downsides of using bioplastics?

Although bioplastics offer advantages, we should consider certain things. Although they contribute to addressing plastic waste, they don't provide a complete solution. Here are key points to keep in mind:

Biodegradability presents a challenge. While designed to break down, many bioplastics require specific conditions, such as industrial composting facilities, for proper decomposition. Incorrect disposal can result in contributing to pollution and landfill bloat.

Land and water usage in bioplastics production are other concerns as these are valuable resources. Luckily, the land used to cultivate renewable raw materials for bioplastics production represents around 0.01% of arable land worldwide.