Plant-Based Polymers to Produce Biodegradable Plastics

Renewable, Nature-Derived Polyesters Degrade in Water and Have High Heat Resistance to Replace Conventional Polymers in Commodity Plastics

These polymers derive from renewable camphoric acid to produce commodity plastics that degrade in water and exhibit high heat resistance comparable to acrylic glass and polystyrene foam. Plastic is an essential material for almost all industries, including the sizeable packaging, building and construction, and automotive industries. Analysts expect the global plastics market to grow to $715 billion by 2025. While the plastic industry is prolific, it is also the source of major environmental issues. Most common commercial plastics derive from nonrenewable fossil fuels that require environmentally harmful processes to extract. They also have low recycling rates and take hundreds to thousands of years to degrade. Available renewably sourced polymers do not have thermal properties suitable for many high heat commercial applications such as transportation. Other polymers, despite being fully plant-based, do not biodegrade easily, and their products often end up in landfills just like conventional plastics.


Researchers at the University of Florida have developed biodegradable plant-based polymers from natural camphor, a product of the camphor laurel tree, and now derived from the pinene in turpentine in scalable quantities. Camphor is one of the most common commercial aroma chemicals, so it is cheap and easy to access. The synthesized polymers form plastics products that are water-degradable and highly heat resistant.

 

Application

Plant-based biodegradable commodity plastic replacement for packaging, bottles, bags, utensils, etc.

 

Advantages

  • Sourced from biorenewable camphor, providing an unlimited supply of material and price stability
  • Degrades in water, producing plastics that undergo environmental self-remediation
  • Achieves glass-transition temperatures better than polystyrene and PET, supporting fully plant-based plastic substitutes for high heat commercial applications, including hot food and beverage applications
  • Replaces nonrenewable terephthalic acid in PET, increasing the bio-based content of PET plastics

Technology

These biodegradable polymers derive from natural camphor (found in the camphor laurel tree), which is presently made by the flavoring/aroma industry from the terpene alpha-pinene found in turpentine. A kilogram of camphor costs $3, which is competitive with the low-cost nonrenewable substances common in plastic production. The nitric acid oxidation of camphor yields the camphoric acid monomer, which reacts with a diol using a catalyst to yield the final polyester material. Combining camphoric acid with different diols yields polyesters with a variety of properties. The polyesters have a high glass-transition temperature, making them as robust as many as fossil fuel based plastics. Polyethylene terephthalate (PET) is a common recyclable plastic used to package electronics, food, bathroom, and cleaning products. Replacing the terephthalic acid in PET with camphoric acid forms polyethylene camphorate, which degrades easily by agitation in water over just 14 days. This duration can be extended with other copolymer formulations. Other combinations yield polyesters with heat resistance exceeding that of polystyrene (95 °C) and PET (72 °C). The versatility of camphor makes it a perfect monomer for synthesizing plant-based, biodegradable polyesters with commercially attractive properties.

Patent Information: