Transitioning to Bio-Based Plastics: An Exhibition

Looking at the molecular scale can help us understand how a material can be produced and determine its material characteristics. Further investigation is required to determine whether a material is indeed better based on its chemical structure, raw ingredients, manufacturing process, use, and end of useable life.

Bioplastics are a broad category derived from a variety of resources and processes to achieve diverse properties. Sources of biomaterials range from agricultural, marine, and mineral. Some raw materials may come from a current waste stream, such as agricultural or food waste, furthering the circular economy. This is preferred over products made from raw materials that use land or feedstocks otherwise used for food production.

Polysaccharides are carbohydrates consisting of long chains of sugar molecules. They are the most abundant polymers derived from naturally renewable sources. Common polysaccharides are cellulose, macroalgae, chitin and starch.

Vegetable Oils are lipids, fatty or oily compounds that tend not to be soluble in water. Historically, they have been used as flax-based wood finishes and linoleum flooring.

Proteins are made of amino acids, of which twenty perform different functions within living organisms. Familiar protein fibers, such as sheep’s wool or silkworm silk, contain keratin and have been used as materials for centuries.

In a push to decouple plastic from fossil fuels, there are new biomaterials entering the market. As defined by the Biofabricate and Fashion for Good report, Biomaterials can be any material with a biological association. Specific categories are defined as follows:

• Bio-based materials are “ wholly or partly derived from biomass”. Renewable biomass is a promising ingredient source to replace existing petrochemical products.

• Bio-fabricated materials are grown with living cells and microorganisms such as mycelium.

• Bio-synthetics or bio-based plastics, are synthetic materials created from a biological source, and typically made through the polymerization of bio-based oils.

Bioplastics can offer a lower carbon footprint. According Bioplastics For A Circular Economy,, replacing fossil fuel with sugarcane feedstocks reduces CO2 emissions by 25%. If combined with renewable energies and cutting our consumption of plastics in half, this could increase to a 93% emissions decrease.

Since the mid-20th century, plastics have dominated a wide range of material markets due to their high versatility and performance. However, the majority of plastics are derived from fossil fuels and often include chemicals of concern. The production and recycling of plastics account for 3.4% of global greenhouse gas emissions. Plastics typically take hundreds of years to biodegrade, allowing these chemicals to leach into waterways and soil systems. We currently produce over 400 million tons of plastic waste each year and the global recycling rate is less than 10%. The building industry is the second largest consumer of plastics and uses 70% of worldwide PVC. This is a grave problem.

By 2050, there may be more plastic by weight in the ocean than fish. Traces of nanoplastics and microplastics, small pieces of plastic debris, have even been found in the human bloodstream, lungs, urine and placenta. Plastics are in nearly every product category in design materials today, including paints, finishes, packaging, flooring, and textiles. Over 54% of textile fibers are polyester. The performance of plastics has come at a high cost to both environmental and human health.

“Bio-based” does not necessarily mean bioplastics are safer or more environmentally friendly. Even when products contain bio-based content, they may still contain synthetic components or additives of concern, which can render them comparable in toxicity to petroleum-based products. The process to create bio-based polyurethane, for example, often still includes isocyanates – similar to the production of petrochemical polyurethane.

It is important to look for ingredient disclosure to fully understand health and environmental impacts. This can be challenging. In a rapidly developing field with limited available research, standards and certifications and manufacturers may want to withhold proprietary information from competitors. In many cases, the CAS# or EIN# for a petrochemical product will be identical to its innovative, plant-based replacement.

The USDA Biopreferred label declares the percentage of biobased content based on ASTM 6866 third-party testing and establishes minimum thresholds for bio-based products per product category. However, more global standards are necessary and must be established to clarify lifecycle impacts of bioplastics and other biomaterials.

The end of life is key to evaluating a bioplastic, which should ideally be compostable. “Compostable” specifies that when a material biodegrades, it breaks down completely into natural components like oxygen and hydrogen. Biodegradable means a product can break down within soil or water by naturally occurring organisms. Biodegradability is dependent on the polymer structure and material properties and is not synonymous with bio-based materials; fossil fuel plastics can be designed to be biodegradable and bioplastics can create microplastics if they cannot break down completely.

A bioplastic like PLA, which is currently on the market, can only break down completely within industrial composting facilities. Industrial composting is not readily accessible, and does not have established systems to be viable as an end of life solution. Even when the option to industrially compost is available, bioplastics can look identical to traditional plastics, causing confusion about which product is compostable versus recyclable. Bioplastics are typically not recycled. The ASTM D6400 standard qualifies products as aerobically compostable in municipal and industrial facilities.

It is essential that new plastics are created to be compostable by microorganisms and can completely degrade without these controlled parameters.

A current challenge associated with biomaterials is scale. Natural and agricultural resources require significant infrastructure for scaling up production and manufacturers need a large market share to keep costs low for consumers. Currently, many new bioplastic products are more expensive than their fossil-based counterparts.

Removing all plastics from our economy may not be possible. Yet, replacing the most toxic plastics that contain chemicals of concern, such as PVC, with healthier, biodegradable solutions is essential. Bioplastics are a potential solution when plastic is necessary. We must still reduce our consumption of all plastics and find alternatives for single-use plastics.

The Donghia healthier Materials library is located on Parsons campus. Parsons and The New School community can visit the library during open hours. External visitors can schedule an appointment by emailing: MaterialLibrary@newschool.edu. The exhibition will be on view throughout the Spring semester.
 

To learn more, reference our previous blogs on bio-definitions and the USDA Biopreferred certification.