Background
Polyethylene terephthalate (PET) plastics are some of the most widely used, yet one of the largest plastic polluters globally. PET polymer is the primary component of disposable water bottles, and is a main component in the textile manufacturing industry. These products typically end up in waste dumps and landfills, and are seldom recycled.
There has been recent research on processes to depolymerize or degrade the PET polymer into numerous value-added products to be used as ingredients for other manufacturing processes, such as in asphalt production, or as an intermediate in production of unsaturated polyurethane and polyester resins. One particular chemical recycling process, aminolysis, involves converting PET polymer into amides of terephthalic acid. However, it has not been widely studied, and other chemical recycling processes have taken precedence for bulk recycling of PET polymer.
Invention Description
Researchers at Arizona State University and the National Renewable Energy Laboratory have developed a new method for the aminolysis of PET with long-chain alkyl amines using ethylene glycol as a co-catalyst and co-solvent to accelerate the reaction. This process is conducted at a low reaction temperature and lower reaction times to yield impurity-free terephthalamides by using a library of long-chain primary alkyl amines. The products of this aminolysis process of PET using long-chain amines can be used to increase the fatigue and rutting factor of asphalt, and increase the strength in concrete binders.
Potential Applications:
- Recycling PET waste (e.g., disposable water bottles, textiles, plastic pollution)
Benefits and Advantages:
- Low cost – no expensive catalysts required
- Faster depolymerization kinetics – use of ethylene glycol catalyst
- Effective – provides high purity end products and removes any dyes or added impurities
- Scalable – can be used to depolymerize tons of PET waste effectively
- Simple process – does not require any post-processing
- Value-added end products – can be used in a variety of applications