Riken and others develop plastic material that dissolves in seawater

A team including government-backed research institute Riken has developed a plastic material that is as strong and easy to process as conventional plastics but can be dissolved in seawater in just a few hours.
The findings were published in an online edition of the U.S. journal Science on Friday.
The international team, which also includes the University of Tokyo, hopes that the new material will help reduce environmental pollution, including that caused by microplastics.
Plastics are made up of polymers, which are chains of monomers. Stable and difficult to decompose due to the strong bonds between the monomers, plastics accumulate within the environment when discarded.
Although biodegradable plastics have been developed, the materials tend to have problems with strength. In addition, it takes time for the materials to decompose.
The team led by Takuzo Aida, group director at Riken and distinguished professor at the University of Tokyo, mixed two types of biodegradable naturally-derived monomers in water, where structures of combined monomers formed.
By extracting and drying the structures, the team obtained a colorless and transparent yet highly dense plastic material.
The team found that it can give various properties to the material, such as heat resistance, hardness and tensile strength, by tweaking one of the two mixing monomers.
All these test plastics were comparable to conventional plastics in many aspects, but they broke down into monomers in a few hours when dipped into salt water, according to the team.
Both types of monomers can be acquired at low costs, the team also said.
“The new material is strong enough, so various applications are considered possible,” Aida said.