WASHINGTON, April 26 (Xinhua) -- Chemists with Colorado State University reported on Thursday in the journal Science a step toward waste-free, sustainable materials that may one day compete with conventional plastics.
Eugene Chen, a professor at the university's Department of Chemistry, and his colleague have discovered a polymer with many of the same characteristics in plastics, including light weight, heat resistance, strength and durability.
Also, the new polymer, unlike typical petroleum plastics, can be converted back to its original small-molecule state for complete chemical recyclability, and this can be accomplished without the use of toxic chemicals or intensive lab procedures.
Synthetic polymers include plastics, fibers, ceramics, rubbers, coatings, and many other commercial products. Polymers are a broad class of materials characterized by long chains of chemically bonded, repeating molecular units called monomers.
Chen's lab demonstrated a chemically recyclable polymer in 2015. But it cannot be made without cold conditions, thus limiting its industrial potential. The previous polymer also had low heat resistance and low molecular weight, and was relatively soft.
Chen said, the monomer of new polymer structure can be conveniently polymerized under environmentally friendly, industrially realistic conditions which are solvent-free, at room temperature, with just a few minutes of reaction time and only a trace amount of catalyst.
The resulting material owns a high molecular weight, thermal stability and crystallinity, and mechanical properties that perform very much like a plastic.
Most importantly, according to researchers, the polymer can be recycled back to its original, monomeric state under mild lab conditions, using a catalyst.
Without need for further purification, the monomer can be re-polymerized, thus establishing what a circular materials life cycle, Chen said.
"The polymers can be chemically recycled and reused, in principle, infinitely," Chen added.
However, there is still much work to be done to perfect the patent-pending monomer and polymer production processes, according to Chen.
"It would be our dream to see this chemically recyclable polymer technology materialize in the marketplace," Chen said.
