Plastics are essential to our daily lives, helping in areas like medicine and technology. However, their toughness makes it hard for them to recycle, a big pollution problem. A new study from Osaka University has found a way to create strong plastics that can be easily broken down and recycled into new materials, helping to solve this issue.
Polymers are the main component of plastics. They are long chains of monomers. Existing recycling methods reuse the polymers without breaking them down, and the recycled plastic is usually worse than the original.
Chemical recycling is a modern technique that breaks down plastic into its basic building blocks, or monomers, and then reassembles them into new plastic. While this method usually results in weaker plastics, researchers have found a way to create strong, chemically recyclable polymers that maintain their heat and chemical resistance. This innovation could significantly increase the applications for these types of recyclable plastics.
Lead author Satoshi Ogawa said, “We knew that we needed to make the links between the monomers really strong in harsh environments but easily broken under specific conditions for recycling. We were surprised that no one had tried including a directing group, which would break the strong links only in the presence of a metal catalyst.”
Credit
Mamoru Tobisu, Osaka University
The directing group acts like a lock on the polymer, only opening when the right “key” is present. These polymers can withstand high temperatures and harsh chemicals, but when it’s time to recycle, a nickel catalyst works as the key, unlocking the links and releasing the monomers. This allows the original polymer to be reassembled from those monomers.
Senior author Mamoru Tobisu explained, “It’s a huge step forward to make a tough polymer that can be broken down easily and precisely and recycled into a pristine material in so few steps. This revolutionary design could be used in making high-performance polymers that can be recycled indefinitely with no loss of quality.”
There’s no need for a tradeoff between performance and recyclability. Their design could be applied to various polymers, making many plastics chemically recyclable. This advancement has the potential to significantly reduce plastic pollution and move us closer to a cleaner environment.
Journal Reference:
- Satoshi Ogawa, Hiroki Morita, Yu-I. Hsu, Hiroshi Uyama and Mamoru Tobisu. Controlled degradation of chemically stable poly(aryl ethers) via directing group-assisted catalysis†. Chemical Science. DOI: 10.1039/D4SC04147J