Chemists from IBM Almaden Research Center in San Jose, California, the University of California at Berkeley, the University of Technology in Eindhoven, Netherlands, and the King Abdulaziz City for Science and Technology in Riyadh, Saudi Arabia have developed the first working method to produce thermoset plastics that can be recycled. Thermoset plastics are a common component of unrecoverable plastic across the world. The development was reported in the May 16, 2014, edition of the journal Science.
Thermoset plastics and polymers were thought to be an irreversible reaction at one time. The extent of the cross linking between the individual units of the polymer has been an obstacle to recycling for decades. Nitrogen cross linking is particularly difficult to return to a reusable state. Thermoset polymers include the plastics that make computer parts. Computer waste has become a major component of the material that must be disposed of in landfills due to the stability of thermoset plastics.
The researchers have developed a thermoset technology that is readily amenable to conversion back to the original parts of the polymer. The material can be made in one vessel. The conversion back to a reusable state can be produced with a simple addition of a strong acid with a pH less than two. The original components of the new thermoset plastic are regenerated at acidity that plastics will not encounter in normal use. An added advantage of the new chemistry is the plastics are self-healing. Self-healing means that small damage to the plastic is repaired by the polymer.
This development heralds a new age of plastic chemistry. Recyclable thermosets that replace all presently used thermoset plastics can be adapted from this initial basis. The manufacturer gets the benefit of not making new product. The planet gets the benefit of less plastic waste. The consumer should eventually receive a lower cost as a benefit of this new technology.