Using organic catalysts to make biodegradable, biocompatible plastics

10-Mar-10

Though most discarded plastic water and beverage bottles can be recycled, the resulting second-generation plastic is generally unusable for making new plastic bottles. Second-generation PET is often used to make carpets or fiberfill for coats and sleeping bags because less strength is needed for those products. The recycled PET can also be combined with another polymer to make more durable products including car bumpers or rope. This is because the polyethylene terephthalate (PET) used to make the original bottles is often made using metal oxide or metal hydroxide catalysts that linger in the recycled material and weaken it over time. That means new plastic bottles must be created to keep up with consumers' insatiable thirst for liquid refreshment in disposable containers. A team of IBM and Stanford University researchers report creation of a new family of organic catalysts that could be used to make plastics that is free of metal and fully recyclable. Organic catalysts are those made from carbon, hydrogen, sulfur and other nonmetallic elements; and can rival even highly active metal-based catalysts while being environmentally benign. They also think their research could lead to a new recycling process that can break polymers back down into reusable monomers. IBM plans to launch a pilot PET recycling project in Saudi Arabia. This additional research will help determine whether the new organic catalysts can help develop plastic products that are cheaper and more easily recycled. In an interesting twist for Saudi Arabia, greater use of recycled plastics means there will be less demand for petroleum to make new plastics. The research team’s findings might also lead to a new recycling process that has the potential to significantly increase the ability to recycle and reuse common petroleum and plant-based plastics. Their findings could lead to a new recycling process that reverses the polymerization process to regenerate monomers in their original state, reducing waste and pollution significantly.