A team of researchers at the University of Tokyo created a polymer that can be repaired when broken into two parts, by application of low pressure at room temperature, according to a paper published in the journal Science on December 19, 2017.
The team discovered a new type of plastic that can be healed by simply pressing the broken pieces back together. These researchers discovered that one of the polymers amongst the ones they were investigating glue properties of, was able to mend itself by simply pushing the pieces together.
They found that the hydrogen bonds in this polymer did not crystallize, thus allowing the molecular chains to move freely. This enabled the easy re-forming of bonds under small amounts of pressure. The team settled on a polymer called polyether-thioureas (TUEG3), which offered the best healing properties of those tested, after several configurations.
To test the material, they cut a small tile into to two pieces, later pressing the two pieces together into the original configuration at room temperature, under minimal pressure. The healed tile was able to support a 300-gram weight, 30 seconds from applying pressure.
They discovered that applying pressure for longer periods to time, allows for even stronger bond formations. This eventually, resulted in the material to reach the same degree of bonding it had prior to being cut or broken, after applying pressure for a few hours.
Engineers are attempting to make further advancements with respect to such polymers before they could plan on addressing the problem of broken screens on phones and other portable devices. While some progress has been made, they still need to make these polymers more transparent for potential use in smartphone screens.